To clarity the response of phenols in different organs of L.ruthenicum Murr.to soil salinization.The stems of annual(F₁),biennial(F₂),triennial(F₃)and wild(Q₁),mild(Q₂),moderate(Q₃),and severe(Q₄)salinized soil were used as experimental materials.The quality of L.ruthenicum was evaluated by principal component analysis.It showed that there were significant differences in each index of L.ruthenicum under different treatments.Among the fruits,the content of wild Q₁ calcium and flavonoids(1.623 g/L,73.963 mg/g)was the highest,the content of total phenol,anthocyanin and procyanidins in Q₄ was the highest(2.049 mg/g,151.836 mg/L,286.167 mg/g),in the shoot,calcium content(4.167 g/L)in Q₂ was the highest,the total phenol content of Q₃(0.491 mg/g)was the highest,the content of flavonoids,anthocyanins and procyanidins in Q₄ was the highest(25.704 mg/g,2.463 mg/L,10.208 mg/g),in leaves,the content of calcium and flavonoids(5.469 g/L,34.593 mg/g)was the highest in Q₁,the content of total phenols and procyanidins(0.943 mg/g,21.00 mg/g)was the highest in Q₄,the content of anthocyanin in Q₂ was the highest(2.880 mg/L);among the annual branchs,the calcium content(2.561 g/L)was the highest in F₁,the contents of total phenols,anthocyanins and procyanidins(0.409 mg/g,0.163 mg/L,8.858 mg/g)in F₂ were the highest,the content of flavonoids(34.593 mg/g)in F₃ was the highest.There was a correlation between soil salinity and various indicators. It is significantly positively correlated with the fruit calcium, and extremely significantly positively correlated with the frui flavone and the leaf calcium. The fruit calcium was significantly positively correlated with the leaf calcium, extremely significantly positively correlated with the fruit flavone, significantly negatively correlated with the fruit anthocyanin and the branch flavone, extremely significantly negatively correlated with the fruit proanthocyanidin.

In order to investigate the effects of reactive oxygen species(ROS)on the growth and antioxidant system of sweetpotato under potassium deficiency stress,and further reveal the defense mechanism of ROS regulation in sweetpotato under potassium deficiency stress.This study selected two sweetpotato varieties,Xushu32(low potassium tolerant)and Ningzi 1(low potassium sensitive),as experimental materials.The experiment was conducted in an artificial climate chamber using hydroponic cultivation to ensure consistent environmental conditions.After pretreatment with exogenous H₂O₂ and diphenyl chloroiodate(DPI),ROS inhibitor,the sweetpotato seedlings were subjected to potassium deficiency treatment.The changes in relative H₂O₂ content,antioxidant gene expression levels,and enzyme activity indicators in sweetpotato roots at different time points after potassium deficiency treatment were measured.The morphological characteristics of sweetpotato were recorded to explore the effects of ROS signaling on the growth of sweetpotato seedlings under potassium deficiency stress.The results showed that under potassium deficiency treatment,the biomass of sweetpotato decreased and leaf color lightened.The relative concentration of ROS in sweetpotato seedling roots showed the highest fluorescence intensity on the 14th day.The expression levels of antioxidant-related genes in sweetpotato roots generally increased,with a more significant increase in expression levels after H₂O₂ pretreatment.Compared with-K treatment,both H₂O₂ and DPI pretreatment could enhance the activity of antioxidant enzymes in sweetpotato leaves,and different enzyme activities showed different trends within 21 days of potassium deficiency treatment.There were varietal differences in the effects of different treatments.The experimental results showed that H₂O₂ could act as a stress signaling molecule to increase the expression level of antioxidant genes and the enzymatic activities of APX,SOD and POD in sweetpotato seedlings,thus scavenging excess ROS and effectively alleviating the inhibition of growth of sweetpotato seedlings by potassium deficiency stress.And DPI could inhibit the production of endogenous H₂O₂,maintain the antioxidant enzyme activity,protect the ROS enzymatic scavenging system of sweetpotato seedlings and avoid oxidative damage to tissues.

In order to investigate the optimal application period of allantoin,Sweet Research No.8 was used as the experimental material in saline soil located in Wuma Village,Shangjia Town,Zhaodong City,Heilongjiang Province.Six treatments were established:spraying with a mass concentration of 0.1 mmol/L allantoin at the seedling stage(M),leaf tufts rapid growth stage(Y),tuber expansion stage(K),seedling stage + leaf tufts rapid growth stage(MY),and seedling stage + leaf tufts rapid growth stage + tuber expansion stage(MYK),and a control group was sprayed with water(CK).The effects of allantoin spraying on the photosynthetic characteristics,antioxidant enzyme activities and tuber yield indexes of sugar beet were determined at different periods.The results showed that the chlorophyll content of allantoin treatment increased compared with that of CK,and with the MY treatment being 27.8%,12.4%,21.8%,and 32.2% higher than the MY treatment in all periods;the stomatal conductance of allantoin sprayed treatments,RuBP enzyme activity,transpiration rate,photochemical quenching capacity,actual photosynthetic efficiency,and antioxidant enzyme activity were all differently enhanced compared with that of CK;the nonoptical quenching capacity,malondialdehyde content,and intercellular CO₂ concentration were lower than CK,with the MY treatment having the best effect,and there was no significant difference between the MYK and MY treatments.Compared with the CK treatment,the yield of MY-treated tubers increased by 26.6%,and the sugar yield increased by 21.3% percentage points.In summary,spraying allantoin in the seedling + leaf cluster growth period can effectively alleviate the harm caused by saline stress to sugar beet,thus improving sugar beet yield,and providing a theoretical basis for exogenous allantoin to improve saline-alkali tolerance of sugar beet.

In order to investigate the impact of different environments on the symbiotic nodulation ability of soybean-rhizobia and to screen suitable culture conditions for symbiotic nodulation,this study established 10 treatments based on 4 environmental factors(culture temperatures:22,26,30 ℃;culture substrates:vermiculite,vermiculiteand nutrient soil;inoculation periods:0 day post-inoculation,inoculation at 10 days;final bacterial concentration:OD₆₀₀=0.5,OD₆₀₀=0.9,OD₆₀₀=1.3),resulting in 36 different culture conditions.Five nodulation-related phenotypes of soybean-rhizobia were measured under these conditions,including the number of nodules per plant,nodule dry weight per plant,nodule size,SPAD of leaf growth at 10 and 24 days post-inoculation(DPI).Principal component analysis,fuzzy mathematics membership function method,and cluster analysis were employed to comprehensively evaluate and classify the symbiotic nodulation ability of soybean-rhizobia under different conditions.A comprehensive evaluation system for the nodulation ability of soybean-rhizobia was established,and the optimal culture conditions were selected based on the comprehensive evaluation index D value.The results showed that culture temperature was the primary environmental factor influencing the symbiotic nodulation of soybean-rhizobia.The maximum values of the number of nodules per plant,nodule dry weight per plant,nodule size,SPAD of leaf growth at 10 and 24 days post-inocubion corresponded to culture temperatures of 30,26,26,30 and 26 ℃,respectively,under,different culture conditions.Under the culture conditions set,the optimal culture temperature for the symbiotic nodulation of soybean-rhizobia was 26 ℃.Multivariate linear regression analysis and grey relational analysis based on the comprehensive evaluation index D value indicated that nodule dry weight and nodule size had a strong correlation with the symbiotic nodulation ability of soybean-rhizobia,serving as important reference indicators for nodulation ability identification.The results of this study established a comprehensive evaluation system for the symbiotic nodulation ability of soybean-rhizobia,providing a theoretical basis for selecting phenotypes and culture conditions for nodulation ability identification.

Calcium-dependent protein kinases(CPK)are a class of protein kinases that respond to calcium signals and participate in regulating the polar growth of pollen tubes,which is crucial for plant reproduction and is precisely controlled by calcium signals and the cytoskeleton.To reveal the function of CPK in the polar growth of pollen tubes in Arabidopsis,bioinformatics methods were used to analyze the expression patterns and evolutionary relationships of CPK family members,and constitutively active(CA)and dominant-negative(DN)CPK17 mutants were constructed.Based on gene gun technology,we observed the phenotypic changes of CA-CPK17 and DN-CPK17 overexpressing pollen tubes,compared the effects of high and low calcium stress on the growth of CPK17 and CA-CPK17 overexpressing pollen tubes,and analyzed the co-expression of CPK17 and its homologous protein CPK34.Additionally,the protein interaction network of CPK17 was predicted,and some of the interacting proteins were validated.The results showed that there were seven pollen-specifically expressed CPKs in Arabidopsis thaliana.Among them,CPK17 and CPK34 had a high similarity (93%),and were highly expressed in mature pollen,and low or no expression in other tissues.Overexpression of CPK17 had no significant effect on pollen tube growth,while CA-CPK17 caused depolarized growth and tip swelling of pollen tubes,and DN-CPK17 had no obvious effect.Overexpression of CPK34 also caused similar defects in pollen tube growth,and co-overexpression of CPK17 and CPK34 aggravated the defects.Calcium stress experiments showed that overexpressing CPK17 pollen tubes were insensitive to low calcium conditions,but sensitive to high calcium conditions.While pollen tubes overexpressing CA-CPK17(lacking the regulatory domain)were insensitive to both high and low calcium conditions.The predicted interacting proteins of CPK17 were mainly ROP negative regulators,but yeast two-hybrid experiments failed to confirm the interaction.These results indicated that the C-terminal regulatory domain of CPK17 plays an important role in the response to calcium signals.CPK17 and CPK34 have synergistic effects on pollen tube growth,possibly by regulating calcium influx and affecting intracellular calcium gradient.

The pollen tube is one of the important structures for plant sexual reproduction,and its growth requires precise coordination of intracellular and extracellular signals.Calcium ions(Ca²⁺)as an important second messenger play a crucial role in various stages of pollen tube growth.Ca²⁺ enters the cytoplasm through ion channels from the external environment or internal calcium stores,and is then transported out of the cell by calcium pumps and exchangers to maintain the dynamic balance of calcium ions.The coordinated regulation of calcium ion influx and efflux is the key to the establishment and maintenance of calcium ion signaling.Calcium-dependent protein kinases(CPKs)and calcineurin B-like proteins(CBLs)are two important classes of calcium-sensing proteins,which can perceive changes in intracellular calcium concentrations and regulate the polar growth of pollen tubes by phosphorylating downstream target proteins.Specifically,the CBL-CIPK signaling pathway may participate in the regulation of ion balance and vacuolar dynamics,while the CPK signaling pathway may affect the turgor pressure,growth rate and direction of the pollen tube by regulating water channels,nitric oxide synthesis,and ion channels.These calcium signaling molecules have complex regulatory relationships with the small G protein ROP1 and its downstream pathways.In summary,this review summarizes the critical role of calcium signaling in pollen tube growth,and elaborates on the regulatory mechanisms of the CPK and CBL-CIPK signaling pathways,providing important references for in-depth understanding of the molecular mechanisms underlying pollen tube polar growth.

Vernalization is a unique and necessary physiological stage in the growth and development of winter wheat,which determines the ecological adaptability and yield of winter wheat.This paper briefly summarizes the production and application value of vernalization of winter wheat.By summarizing and analyzing the structure and function of the key genes TaVRN1,TaVRN2 and TaVRN3 in wheat vernalization and their regulatory networks,it is believed that the study of epigenetic regulation of TaVRN1 is the core work of wheat vernalization mechanism analysis.Combined with the existing research on the expression regulation of TaVRN1,the causes of the difference in vernalization demand of wheat,the mechanism of long-term low temperature perception in winter,the research progress of overwintering memory and overwintering memory reset after vernalization,and the effect of vernalization on the regulation of cold tolerance,spikelet development,tillering and other agronomic traits of wheat were mainly introduced.In addition,this study summarizes the unsolved scientific problems in vernalization,and discusses the future research direction of wheat vernalization,which provides reference suggestions for the research of high yield and rapid breeding of wheat.

The effects of sowing date on the yield and yield components of winter wheat,and the response characteristics of growth and development and plant type structure to accumulated temperature were studied in order to clarify the growth characteristics and reasonable plant type structure of wheat adapting to climate change.From autumn 2017 to summer 2019,field trials were conducted in Gaocheng,Hebei Province.Five sowing dates were set,September 25,October 5,October 15,October 25 and November 4.The results showed that the yield of wheat was higher sown from October 5 to 15 than other treatments,and the accumulated temperature before winter was 410-549 ℃.When accumulated temperature before winter was suitable,spike number was high and grain number per spike was moderate.When the accumulated temperature was as high as 733 ℃,the number of invalid tillers was more,the effective tiller rate was lower,and spike number was lower.When the accumulated temperature was insufficient to 279 ℃,the spike number and grain number per spike decreased.Accumulated temperature had a significant effect on growth and development indicators.Under the condition of high and stable yield,the individual index of wheat before winter was put forward:the number of main stem and tillers per plant was 2.3,the number of secondary roots was 2.5,the number of leaves of main stem was 4.1,and the spike differentiation of over winter was single edge stage.The accumulated temperature had an obvious effect on the plant structure of wheat.Delay with sowing date,the flag leaf became longer and wider,the leaf area increased,and the leaf from the top third to the top fifth became narrower and the leaf area decreased.Delay with sowing date,stem diameter of the base increased,the stem length of the top first to top second increased and length of the top third to top fifth decreased,and plant height decreased significantly.According to the equation of yield and accumulated temperature before winter,it was recommended that the suitable sowing time of wheat was October 8 to 14 under high and stable yield conditions,and the accumulated temperature range before winter was 433-541 ℃.Under late sowing conditions,the plant type structure was more reasonable,the growth and development of the plant were moderate before winter,the flag leaf was smaller and its stem length was shorter,and the leaf from the top third to the top fifth from the top was larger and their stem was slightly longer.

Cd-sensitive wheat CM28 was used as the research object to investigate the effects of spraying exogenous glycine on its physiological and biochemical processes under different concentrations of cadmium stress.The plant height and root length,above-ground transport coefficient and enrichment coefficient of cadmium,chlorophyll content and malondialdehyde(MDA)content,and the enzyme activities of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)of CM28 under different treatments were determined.The expression levels of PEPC genes in roots and leaves under different treatments were analyzed by qRT-PCR.The results showed that under 30 μmol/L Cd stress,the spraying of exogenous glycine led to a decrease in the above-ground dry and fresh weights,a decrease in the total-chlorophyll content,and an increase in the MDA content of CM28,indicating that plants were affected by more reactive oxygen species.Under 50 μmol/L cadmium stress,glycine could effectively alleviate the negative effects of cadmium on CM28,resulting in an increase in the total-chlorophyll content,an increase in the above-ground dry and fresh weights,and a decrease in MDA content,suggesting that the plant was affected by reactive oxygen species to a greater extent.The antioxidant enzyme activity of CM28 increased with the increase of cadmium concentration,and the spraying of exogenous glycine could enhance the activity of antioxidant enzymes and alleviate the effect of cadmium on the whole.The expression of PEPC genes in roots increased overall with the rise of cadmium concentration,indicating that PEPC played an important role in the process of plant root resistance to stress,and the spraying of exogenous glycine can also effectively alleviate the cadmium stress on CM28 and reduce the expression of PEPC genes on the whole.In summary,cadmium stress negatively affects the physiological and biochemical processes of CM28,and the spraying exogenous glycine can alleviate the effects.

In order to determine the effect of different size ear grain characteristics on the mechanical grain crushing rate of corn,Xianyu 1171 and Zhenghong 505 were used as experimental materials to divide the ear into large ear,middle ear and small ear,and determine the agronomic traits,mechanical strength,grain water content and grain crushing rate of corn ear at different harvest periods.The variation of grain water content and mechanical strength of corn with different size ears was studied,and the effect of ear size on the crushing rate of corn with mechanical grain harvesting was analyzed.The results showed that the grain breakage rate of Xianyu 1171 decreased first and then increased slightly,and the grain breakage rate of Zhenghong 505 decreased,and the difference of grain breakage rate between varieties gradually narrowed.The grain breakage rate of spicles was significantly lower than that of middle ear and big ear, and the grain breakage rate of Zhenghong 505 decreased by 16.98 and 20.96 percentage point compared with that of middle ear and big ear,respectively.The grain breakage rate of Xianyu 1171 decreased by 18.63 and 22.43 percentage point compared with that of middle ear and big ear.The grain water content of Zhenghong 505 was significantly higher than that of Xianyu 1711.The grain water content of Xianyu 1171 was mostly mostly significantly higher than that of middle ear and big ear,while that of Zhenghong 505 was lower than that of middle ear and big ear.The endosperm puncture strength of spicule Xianyu 1171 was mostly significantly lower than that of middle panicle and big panicle,but there was no significant difference in crushing strength.There was no significant difference in grain mechanical strength among panicle sizes of Zhenghong 505.Correlation analysis showed that grain breakage rate was significantly of extremely significantly positively correlated with water content,ear length,ear diameter and ear volume,but extremely significantly negatively correlated with grain mechanical strength.Moderate reduction of ear length,ear diameter and ear volume of corn can significantly reduce the crushing rate of corn grain in mechanical grain harvesting.Therefore,it is an effective measure to reduce grain crushing rate by selecting small ear corn varieties or reducing ear size by increasing density and other cultivation measures.

Low temperature stress seriously affects the safe production of rice,especially machine-transplanted rice.In order to clarify the suitable plant growth regulator and spraying periods for machine-transplanted double-cropping rice,the early rice variety Zhongjiazao 17 and the late rice variety H you 518 were used as materials.The effects of different plant growth regulators(Uniconazole,C1;Abscisic acid,C2;Zhuanggubao,C3)and spraying periods(early rice:soak seeds,D1;one leaf and one core stage,D2;two leaves and one core stage,D3;before transplanting,D4;during the greening stage,D5;late rice:booting stage,F1;initial heading stage,F2;full heading stage,F3;one week after full heading,F4)on the yield and cold-resistant characteristics of machine-transplanted rice were studied.The results showed that among the three plant growth regulators,the Zhuanggubao treatment had the largest number of stems and tillers,the highest leaf area index,and the largest dry matter accumulation,which were significantly higher than the other two treatments.The yield of Zhuanggubao was the highest.The actual yield of early rice was 7.58% and 7.13% higher than that of uniconazole and abscisic acid treatments respectively.The actual yield of late rice was 13.54% and 11.59% higher than that of uniconazole and abscisic acid treatments respectively.In terms of spraying period,early rice was sprayed at the greening stage,and late rice was sprayed at the initial panicling stage,which had the best effect on improving various indicators of yield and the highest yield.Analyzing the components of yield,plant growth regulators and spraying periods mainly increased yield by increasing the number of grains per panicle of rice.The SOD,POD and CAT activities of early and late rice were highest in the grain-stuffing treatment.At the same time,spraying plant growth regulators during the greening stage of early rice and spraying plant growth regulators at the beginning of earing stage of late rice were more effective in increasing antioxidant enzyme activity.Taken together,the plant growth regulator for double-cropping machine-transplanted rice in Southern Hunan is Zhuanggubao,and spraying during the greening stage of early rice and spraying at the beginning of earing stage of late rice have the best cold-resistant and yield-increasing effects.

To select the suitable sorghum varieties for brewing in Qitai County,and provide reference for breeding and generalization of the new sorghum varieties in Xinjiang,20 new sorghum varieties were introduced from other provinces and their growth periods,agronomic traits and yields were compared to identify the highest and stable yield of each variety in 2020-2022.And the nutritional qualities such as grain starch,lysine,tannin,soluble total sugar,crude protein,crude ash and crude fiber were measured.The results showed that the growth period,agronomic traits,yields and nutritional composition were different between varieties and planting years.The average growth periods of 20 varieties were 84-146 days and plant heights ranged from 68.44 to 250.46 cm.The two species,Longza 18 and Longza 20,belonged to extremely early maturing and short varieties.The 13 short stem varieties with plant heights of less than 150 cm were identified as suitable for mechanized cultivation,such as Fengza 4,Liaonuo 11,Jiza 124,Jiza 127,Liaoza 37,Liaonian 3,Jiniang 3,Jinza 34,Jinnuo 3,Tongza 108,Jinza 109,Chiza 106 and Jinnuoliang 5.Hongyingzi was the only late-maturing high-stem variety.The yield ranged at 4 364.32-13 779.84 kg/ha,Jinza 109 had the highest yield while Shenza 5 had the lowest yield.There were differences in grain quality among different varieties;Liaoza 10 had the highest starch content of 759.93 g/kg while Jinza 34 had the lowest tannin content of 1.81 g/kg.In summary,based on the characteristics of growth period,agronomic traits,yield and quality,the tested short-stem and mid-mature variety Jinza 109 showed the highest yield,best stability and best comprehensive performance,which can be planted and popularized as the preferred variety suitable for mechanized cultivation in the Qitai area.

In order to study the problem of strong winter/spring Brassica napus seed germination and flowering period under different winter sowing dates.Two strong winter rapeseeds and two spring rapeseeds provided by Gansu Agricultural University were used as materials.The experiment was carried out in the experimental field of Gansu Agricultural University from October 2022 to August 2023.The winter rapeseeds was carried out on October 11,2022.The winter/spring rapeseeds was sown every 20 days from December 10,2022,and the sowing ended on February 8,2023.The flowering period was recorded,and the germination seeds of winter rapeseed were sampled every 20 days to determine their physiological and biochemical characteristics and analyze the expression characteristics of vernalization genes(FLC,VRN2,FRI,FT).The results showed that the flowering period of winter/spring rape seeds was different by 22—34 days.The difference of flowering time between autumn sowing and spring sowing was 4—7 days.The flowering time of winter rapeseed in autumn sowing(October 11 th)was close to that of spring rapeseed under different winter sowing dates(December 10th,December 30th,January 19th,February 8th),and the flowering overlap time was as long as 15—20 days.With the delay of the sowing date,the relative expression levels of FLC,FRI and FT genes in germinating seeds of winter sowing were down-regulated.The relative expression of VRN2 gene was down-regulated in the early vernalization and up-regulated in the late vernalization.The activities of superoxide dismutase(SOD),peroxidase(POD),catalase(CAT)and the contents of soluble protein(SP),gibberellin(GA3)and salicylic acid(SA)in germinating seeds were increased in the early vernalization,but those were decreased in the late vernalization.The contents of malondialdehyde(MDA)and abscisic acid(ABA)were increased in rapeseed germinating with the increase of vernalization time.

This study explored the effects of intercropping and rotation on the growth,yield and quality of continuous cropping peanut,to provide theoretical basis for achieving high yield in peanut production.From 2022 to 2023,sweet potato-peanut rotation system(PSP)and maize-peanut intercropping and rotation system(PMP)were set up in the experimental farm of Henan University of Science and Technology on the basis of continuous cropping peanut for 2 years and 11 years respectively,with continuous cropping peanut as control(CCP1 and CCP2,respectively).The effects of PSP and PMP on photosynthetic characteristics,root characteristics,dry matter accumulation and distribution and yield of peanut were studied.The results showed that compared with CCP1,the leaf area index(LAI)of rotating peanut in PSP system(SRP)was significantly increased by 35.08%—53.68% and 24.32%—33.52% at pod-setting stage(PSS)and full pod maturity stage(PMS),respectively.The SPAD value at PSS and pod bulking stage(PBS)increased by 11.93%—18.55% and 5.95%—9.63%,respectively.Compared with CCP2,the LAI of rotating peanut in PMP system(MRP)increased by 46.81%—57.96% and 27.00%—61.78% at PSS and PMS,respectively.At PSS and PBS,compared with CCP2,the SPAD value of MRP and intercropping peanut(MIP)increased by 3.32%—3.69%,7.50%—8.64% and 5.47%—18.37%,15.73%—31.11%,respectively.At PSS and PBS,compared with CCP1,the net photosynthetic rate of SRP increased by 23.68%—41.31% and 26.52%—32.55%,and compared with CCP2,MRP increased by 12.77%—17.81% and 16.88%—62.07%,respectively.They both significantly improved the root length and root tip number,and promoted the dry matter accumulation and the distribution to pods during PMS,and the yields increased by 31.42%—47.36% and 54.12%—75.09%,respectively.Compared with CCP2,MIP reduced the LAI,net photosynthetic rate,root length,root tip number,as well as dry matter accumulation and yield of peanut under the influence of maize shading.At the same time,the content of peanut oleic acid and oleic acid-linoleic acid ratio was significantly increased after rotation.Among them,SRP increased by 1.63—1.65 percentage point and 6.59%—10.52%,respectively,compared with CCP1,and MRP increased by 1.95—2.82 percentage point and 9.75%—14.16% compared with CCP2,respectively.In summary,sweet potato-peanut rotation and maize-peanut rotation increased the peanut yield compared with continuous cropping peanut,the reason was that sweet potato-peanut and maize-peanut rotation promoted peanut root growth,delayed the leaf senescence,and increased photosynthetic rate,especially the photosynthetic rate during late growth period,which promoted the dry matter accumulation and distribution to seeds.Besides that,they could improve the quality of peanut to a certain extent.

In order to explore the improvement effect of calcium fertilizer and ARC microbial agent on red earth dry land with low-calcium,the peanut variety Xianghua 522 was used as the experimental material,and two levels of calcium hydroxide fertilizer(0,750 kg/ha,code Ca₀ and Ca₅₀)and three levels of ARC microbial agent(0,30,60 kg/ha,code A₀,A₂ and A₄)were set to form six treatments to carry out pot experiment.It measured soil nutrient and soil enzyme activity in 0—20 cm arable layer soil at peanut seedling stage,flowering stage,pod setting stage and pod filling stage,and pod economic characters and yield were measured at harvest.The results showed that:single application of calcium fertilizer and the combined application of calcium fertilizer and ARC microbial agent could significantly improve the pH of soil at all growth stages,but ARC microbial agent had little effect on it.Compared with CK(Ca₀A₀),Ca₅₀A₂ and Ca₅₀A₄ significantly increased the content of hydrolyzable nitrogen in soil in the whole stage and the content of available phosphorus in soil in the first three growth stages;the content of available potassium in soil of Ca₅₀A₄ was higher than CK in general,and it was significant at seedling stage and pod setting stage;compared with CK,Ca₅₀A₀ significantly increased the content of exchangeable calcium in soil in four stages,with an increase of 23.78%—56.21%;the content of calcium ion in soil with calcium fertilizer application was significantly higher than that without calcium fertilizer application(the flowering stage was not significant),and it was little affected by ARC microbial agent;the content of organic matter in soil remained stable in the whole growth stage,but Ca₅₀A₄ and Ca₅₀A₂ were significantly higher than CK in each growth stage.Compared with CK,the soil sucrase activity of soil each treatment was significantly increased in four stages,and the increase was the largest in Ca₅₀A₄,ranging from 50.79% to 162.56%;the protease activity of soil was significantly increased by Ca₅₀A₂ in four stages with an increase of 26.58%—244.63%;the acid phosphatase activity of soil was significantly increased by Ca₅₀A₄ and Ca₀A₂ during the whole growth stage;the catalase activity of soil in all treatments showed a decreasing trend in general.All treatments could increase the yield of peanut pod in different degrees,and the effect of calcium fertilizer application was greater than that of ARC microbial agent,among which Ca₅₀A₄ had the best effect,with the pod weight per plant increasing by 12.29%,mainly increased the pod number per plant and the full pod number per plant.To sum up,the combined application of calcium fertilizer and ARC microbial agent has a good interaction effect on improving soil nutrient content,stimulating soil enzyme activity and increasing peanut yield,and the best effect is 750 kg/ha calcium fertilizer+60 kg/ha ARC microbial agent(Ca₅₀A₄),which can provide a theoretical basis for green and high yield cultivation of peanut.

To explore the planting patterns of mechanical harvesting sesame and achieve goals of high yield,stable yield and deep combination of agricultural machinery and agronomy,the split plot design with two factors was carried out to investigate the effects of different planting pattern and density on the photosynthetic characteristics,biomass,yield and mechanical harvesting characteristics of Yuzhi ND837,in order to provide theoretical foundation and technical guidance for the full mechanization production of sesame.The planting pattern included wide-and narrow-row spacing planting(Z1,wide-row:60 cm,narrow-row:20 cm),banding planting of 4 rows(Z2,line spacing:30 cm,banding spacing:60 cm),banding planting of 8 rows(Z3,line spacing:30 cm,banding spacing:60 cm)and equidistant row planting(Z4,line spacing:30 cm)as primary area.The planting density included 180(M1),225(M2),270(M3)and 315 thousand plants/ha(M4)as vice-area.The results showed that planting pattern and planting density both had significant effects on the photosynthetic characteristics,substance accumulation,yield and mechanical harvesting characteristics of sesame.The net photosynthetic rate(Pn),SPAD value and biomass per plant descended with the order of M1>M2>M3>M4,while the biomass of population increased at first and then descended with the planting density increasing under the same planting pattern.Under different planting patterns,the Pn,SPAD value,biomass per plant and biomass of population all showed Z1>Z2>Z3>Z4.Under the comprehensive effects of planting pattern and density,the Pn and SPAD value of Z1M1 were the highest,and the biomass per plant was also the highest in Z1M1(59.76 g/plant),but the biomass of population and yield were the highest in Z1M3(13 032.97,1 719.87 kg/ha,respectively).The uniformity of plants tended to be the same,the diameter of stem and the ability of capsule formation per plant decreased,but the lodging percentage at maturity also gradually decreased with the increase of planting density(M1>M2>M3>M4).The lodging percentage showed Z1>Z2>Z3>Z4 among different planting patterns.Under the comprehensive influence of planting pattern and density,the lodging percentage of Z3M1(17.51%)was the highest and Z4M4(7.97%)was the lowest.Under the conditions of the experiment,Z1M3 has the biggest yield,and the agronomic traits and mechanical harvesting characteristics at maturity are also better.

To clarify the effects of sulfur application at different stages on the yield and photosynthetic characteristics of strong-gluten wheat,and to determine the appropriate time for sulfur fertilizer application,from 2019 to 2021 during two wheat growth seasons,using strong-gluten wheat Gaoyou 2018 as the experimental material,three sulfur application periods were set:before sowing (S60-b),topdressing at jointing stage (S60-j),and topdressing at anthesis stage (S60-a),with a sulfur application rate of 60 kg/ha,and no sulfur application (CK) as the control.The effects of leaf area index (LAI),relative chlorophyll content of flag leaf (SPAD),soluble protein content,soluble sugar content,yield and components of strong-gluten wheat under different sulfur application treatments were studied systematically.The results showed that compared to CK,S60-b,S60-j and S60-a could all significantly increase the thousand-grain weight (TGW),maximum grain filling rate and yield of Gaoyou 2018.In the two growing seasons,the average increase of TGW was 6.23%,4.27% and 7.04%,respectively;the increase of TGW was the highest at 35 days post anthesis,which was 5.51%,3.17%and 6.12%,respectively.The average increase of maximum grain filling rate was 2.84%,1.76% and 3.49% and the average increase in yield was 9.20%,2.73% and 5.71%,respectively.However,sulfur application had no significant effect on the number of ears and grains per unit area of Gaoyou 2018.Sulfur application at different stages had significant effects on the photosynthetic characteristics of strong-gluten wheat.The LAI,SPAD value of flag leaves in the middle and late stages of growth,the soluble protein content of flag leaves at 22 and 29 days post anthesis and soluble sugar content in flag leaves at 35 days post anthesis were significantly increased by S60-b and S60-a treatments.The five above indexes increased by more than 26.16%,7.38%,16.90%,55.29% and 81.11%,respectively.According to the results of two years,before sowing and topdressing at the anthesis stage with sulfur fertilizer could significantly increase the LAI of flag leaves in the middle and late growth stage,maintain high SPAD value,delay flag leaf senescence,increase the contents of soluble protein and soluble sugar,TGW and filling rate at the end of grain filling,showing higher yield.In summary,sulfur application have a positive regulatory effect on the yield of strong-gluten wheat,and before sowing and topdressing at the anthesis stage have a good regulatory effect.

Germination control is an important basis for promoting rapid emergence and uniform seedlings of Brassica napus.In order to explore the effect of exogenous sucrose on B.napus seed germination and seedling development,it selected the early-maturing rapeseed variety-Xiangyou 420 to conduct germination tests under different conditions and detected the expression changes of moisture,abscisic acid,endogenous sugars and key genes.The results showed that exogenous sucrose delayed the germination initiation process of Xiangyou 420 seeds,improved the uniformity of germination,promoted the cotyledons to turn green and formed true leaves after the cotyledons expanded,inhibited the excessive elongation of the main root and promoted the development of lateral roots.Exogenous sugar first inhibited and then promoted water absorption during the germination process of Xiangyou 420 seeds.It inhibited water absorption within three hours after sowing and released the inhibition of water absorption within six hours after sowing.The ABA content in seeds continued to decrease during the germination process,and exogenous sucrose promoted the decrease in ABA content within three hours after sowing.The total soluble sugar content decreased rapidly within 15 to 18 hours after sowing,and the reducing sugar content increased with the germination process in the early stages of germination.Exogenous sucrose had no significant effect on the changes in total soluble sugar content but inhibited the increase in reducing sugar content within nine hours after sowing and promoted the increase in reducing sugar content 15 hours after sowing.During the germination process,the expression of two sucrose phosphate synthase (BnaSPS) genes decreased significantly during the radicle germination stage and then increased after the cotyledons turned green.Exogenous sucrose inhibited the expression of the two BnaSPS genes before radicle germination, and significantly induced,the expression of BnaC09g37470D gene after the cotyledons turned green.In summary,it preliminarily reveals that exogenous sucrose regulates water absorption at the initial stage of imbibition through osmotic effects,and delays the initiation of B.napus seed germination by regulating endogenous sugar utilization in seeds during the germination stage and sugar conversion in the early stages of seedling development through sugar metabolism,promotes the seed germination process after imbibition,improves the uniformity of seed germination,and promotes the development of seedlings.

In order to explore the effects of high temperature stress on different heat-tolerant watermelon inbred lines,heat-sensitive (D27) and heat-tolerant (K53) watermelon seedlings were treated at 42 ℃ for 48 h,and their phenotype,tissue structure,photosynthetic characteristics,antioxidant enzyme activities and osmotic regulators were measured and analyzed every 12 h.The results showed that the leaf thickness,fence tissue thickness,sponge tissue thickness and tissue compactness of heat-tolerant K53 were larger than those of heat-sensitive D27 after high temperature stress.The proportion of sponge tissue in the palisade tissue of D27 decreased more than that of K53.With the increase of high temperature stress time,the net photosynthetic rate (Pn),transpiration rate (Tr) and stomatal conductance (Gs) of the two inbred lines decreased,and the intercellular CO₂ concentration (Ci) increased.And the change amplitude of D27 was greater than that of K53.Among the four photosynthetic pigment contents,the heat-tolerant type was higher than the heat-sensitive type under high temperature stress at different treatment times.The superoxide dismutase (SOD) and peroxidase (POD) of the two inbred lines increased first and then decreased with the increase of high temperature stress time,and the enzyme activity was the highest at 24 h,and the enzyme activity of K53 was significantly higher than that of D27.After high temperature stress,the relative conductivity of the two inbred lines increased,and the relative conductivity of K53 increased less than that of D27.The malondialdehyde (MDA) content of D27 was reduced;the MDA content of K53 decreased after an increase.With the increase of high temperature stress,the soluble protein content and proline content (Pro) of K53 were significantly higher than those of D27 at 24 h.In summary,the heat-tolerant type K53 had a stronger resistance to high temperature stress than the heat-sensitive type D27.

To study the effects of ridge height on soil heat status,root growth,and tobacco maturity tolerance in tobacco planting,a 2-year field experiment was conducted using the flue-cured tobacco variety Yueyan 97 as the test material from 2022 to 2023.Three treatments were set up,including a ridge height of 30 cm(CK),a ridge height of 38 cm(T1),and a ridge height of 46 cm(T2),to analyze the changes in soil temperature and heat flux,root appearance and growth indicators,root vitality,and tobacco maturity related indicators under different ridge heights.The results indicated that the daily temperature difference in soil varies with the depth of the soil layer,and the daily temperature difference in the surface layer of the soil was the largest.Increasing ridge height can increase the average temperature of tobacco planting soil by 0.4-1.8 ℃ and increase soil heat flux by 4-56 W/m².In the 2 a experiment,the maximum increase in root length for a ridge height of 38 cm compared to a ridge height of 30 cm was 27.26%,the maximum increase in root dry mass was 26.21%,and the maximum increase in root vitality was 14.97%,with significant differences.Compared with a ridge height of 30 cm,the soluble protein content,peroxidase activity,and cell membrane stability index of a ridge height of 38 cm increased by 17.99%,27.82%,and 9.05 percentage points(2022),respectively and by 10.23%,12.44%,and 8.16 percentage points(2023),respectively.The maximum decrease in malondialdehyde content was 24.84% and 44.43%,respectively.Correlation analysis showed that root activity was significantly negatively correlated with malondialdehyde content,peroxidase activity was extremely significantly positively correlated with root growth indexes, and soluble protein content was significantly positively correlated with root length.In summary,increasing ridge height is beneficial for improving the thermal status of tobacco planting soil,promoting root growth,enhancing root vitality,enhancing leaf antioxidant capacity,and enhancing tobacco maturity tolerance.A ridge height of 38 cm is an appropriate ridge height for promoting root growth and improving tobacco maturity tolerance in southern tobacco regions.

Plant growth and production are faced with various biological and abiotic stresses,among which salt stress seriously affects the normal growth and development,quality and yield formation of plants.Plants have evolved morphological structure,physiological and biochemical reactions and genetic basis to adapt to salt stress during the long process of evolution.In terms of morphological structure,the leaves of salt-tolerant plants have waxy layer and lower stomatal density than those of salt-sensitive plants,and salt glands,microhairs,salt vesicles,and casparian strip have salt secretion or blocking functions.In terms of physiological activity regulation,on the one hand,salt-tolerant plants have high enzymatic and non-enzymatic antioxidant substances,such as SOD,CAT,phenolic substances,on the other hand,salt-tolerant plants have a high content of osmoregulatory substances,or can synthesize osmoregulatory substances under salt stress,including soluble proteins and sugars of organic substances and inorganic ions.In terms of molecular mechanism,SOS pathway is the most clearly studied ion regulation pathway,which maintains intracellular Na⁺/K⁺ balance through the synergistic action of SOS1,SOS2 and SOS3.In addition,plant hormones and carbon metabolism pathways also play an important role in the process of plant salt tolerance.This paper summarizes the research progress of salt-tolerant plants,and discusses the potential research focus and direction of salt-tolerant plants in terms of morphological structure,physiological basis,genetic molecular basis and transgenic methods in response to salt stress,which will help researchers quickly find the breakthrough point,gradually improve the mechanism system of salt-tolerant plants,and accelerate the efficient utilization of salt-tolerant plants.

In order to investigate the physiological regulation mechanism of exogenous H₂O₂ on the cotton seedlings under NaCl stress,the cotton variety Xinluzao 48 was used as the test material in an outdoor potting method.Two-factor random combinations of salt stress (NaCl,concentration gradients of 0,100,200 mmol/L) and H₂O₂ (concentration gradients of 0,0.005,0.010,0.020,0.050 mmol/L) were set,to study the change rule of fresh weight,dry weight,chlorophyll content,chlorophyll fluorescence parameters,photosynthetic gas parameters,antioxidant enzyme activities and osmotic regulation system of cotton seedlings.The results showed that exogenous H₂O₂ effectively alleviated the inhibitory effect of salt stress on the growth of cotton seedlings,increased chlorophyll content,photosynthetic gas parameters and chlorophyll fluorescence parameters of cotton seedlings,maintained the normal operation of photosynthesis of cotton seedlings and ensured the accumulation of dry matter.Meanwhile,exogenous H₂O₂ could increase the activity of antioxidant enzymes (POD,APX,CAT),accelerated the removal of ROS from cotton seedlings.Exogenous H₂O₂ reduced the electrolyte leakage rate,MDA content,the content of osmoregulation substances such as pro,free amino acid and SS,and improved the salt resistance of cotton seedlings.Among all treatment,0.020 mmol/L exogenous H₂O₂ had the best effect in alleviating the salt stress suffered by cotton seedlings.In summary,exogenous H₂O₂ improves the adaptation of cotton seedlings to salt stress by improving photosynthetic performance,keeping stable photosynthesis in cotton seedlings,and maintaining the dynamic balance between ROS production and elimination in cotton seedlings.

Clarifying the effect of spring limited irrigation on the root development and grain yield of winter wheat in Haihe Plain is of great significance to reduce irrigation and improve water use efficiency.This study used Shimai 22 as the test material,irrigation treatments were traditional irrigation twice at jointing and anthesis stage(W2),no irrigation(W0),and single irrigation(W1)with four irrigation-time treatments(3L,4L,5L,and 6L)based on the number of leaves unfolded in spring.The results showed that compared with W2,W0 and W1 yield decreased by 54.6% and 24.4% respectively,the irrigation yield was highest at 4L in W1,and the effect of yield composition reduction was not significant.Limited irrigation reduced the total root weight density and root length density of winter wheat.During the anthesis period, the total root weight density of W1 decreased significantly by 17.2%, while the total root weight density and root length density of W0 decreased significantly by 47.5% and 35.1%, respectively. And under W1 condition, 4L has the highest total root weight density and root length density. The vertical distribution of roots showed that reducing the frequency of irrigation increased the distribution of roots in the soil layer below 40 cm,however,with the postponement of irrigation time,the root distribution of W1 deep soil decreased and root vigor increased.Among them, during the anthesis period, 4L was significantly higher than 6L by 28.8%, 14.2%, and 36.5% in the 120—160 cm, 160—200 cm, and 200—240 cm soil layers, respectively. Correlation and path analysis showed that total root weight density and root length density at joint—anthesis period had a positive effect on yield.The direct contribution of total root length density in 3L and 4L irrigation was the largest.Generally speaking,the root mass of 4L treatment was higher at jointing-anthesis period,the deep root distribution and root activity of 40—240 cm were increased,resulting in higher spike number and kernel number,which was beneficial to alleviate the decrease of winter wheat yield at limited irrigation,it can be used as an effective way of limited irrigation for winter wheat in Haihe Plain.

In order to investigate how to alleviate the effects of insufficient light in potato production,the potato variety Dongnong 310 was used as the test material,and three shading treatments were set up:normal light(Z₀,blackout rate is 0),single-layer blackout screen covering treatment(Z₁),double-layer blackout screen covering treatment(Z₂).Different concentrations of epbrassinolide(0 mg/L,denoted as CK)were sprayed in the potato tuber formation stage(0.02 mg/L,denoted as E₁;0.10 mg/L,labeled E₂).Three measuring periods were set,the plant height,chlorophyll a,b content,photosynthetic parameters,fluorescence kinetic parameters,and yield per plant were measured and analyzed.The relative expression levels of LHcb genes in 12 leaves were measured.The results showed that Z₁ conditions were more suitable for the growth of Dongnong 310,while Z₀ conditions produced photoinhibition,and the indexes were lower than Z₁.Under the condition of Z₂,the illumination was insufficient,and the indexes were lower than that of Z₁.EBR spray could effectively increase the yield per plant,and E₂ treatment under Z₀ condition significantly increased by 32.62% compared with CK,E₁ and E₂ treatment under Z₁ condition significantly increased by 48.38% and 24.24% compared with CK,respectively,E₂ treatment under Z₂ condition significantly increased by 18.45% compared with CK.In terms of weight of dry matter per tuber,E₂ treatment under Z₀ condition increased by 27.24% compared with CK,and E₁ and E₂ treatment under Z₁ condition increased by 40.09% and 26.56% compared with CK,and the above differences were significant.The relative expression of 12 LHcb genes could be increased by increasing the shading degree and spraying EBR,which was conducive to improving the light energy capture and utilization in leaves.

In order to explore the molecular mechanism of low nitrogen response in quinoa, low nitrogen response genes were screened to reveal the adaptive changes in quinoa response to low nitrogen.Based on the seedling growth observation and chlorophyll synthesis detection,we analyzed the transcriptome changes of quinoa after 5 d and 30 d under nitrogen deficiency conditions.The results showed that roots were preferentially developed under nitrogen starvation condition.Older leaves turned yellow or dropped down under both low nitrogen and nitrogen starvation conditions,therefore younger leaves could maintain green.Higher NUE was shown in both low and nitrogen starvation conditions.GO enrichment analysis indicated that significantly differential expressed genes were mainly involved in integral component of membrane,membrane,oxidation-reduction process,metabolic process,ATP binding,and metal ion binding.After 5 d of low or nitrogen starvation supply,KEGG enrichment analysis showed that phenylpropyl biosynthesis and glutathione metabolism were the most significant metabolic pathways compared with high nitrogen.After 30 d of treatment,the most significant metabolic pathway was the carbon metabolic pathway.The key genes in response to low nitrogen in quinoa were further explored.The results showed that peroxidase,glutathione S-transferase and ascorbate peroxidase genes were up-regulated and their expressions were higher after 5 days of low nitrogen and nitrogen deficiency treatment.The genes of phosphoglycerate kinase,cysteine synthetase,glyceraldehyde 3-phosphate dehydrogenase (NADP)and phosphoenolpyruvate carboxylase were up-regulated and the expression levels were higher after 30 days of low and low nitrogen treatment.The results of qRT-PCR agreed with the RNA-Seq.

In order to reveal the physiological mechanism of winter rye in response to low temperature stress,the physiological changes of osmoregulatory substances and antioxidant enzyme activity in the leaves and tillering nodes of Wintergraze 70 and White BK-1 were compared during the cold hardening and rejuvenation periods.The results showed that during the cold hardening period,rye mainly improved its cold resistance by accumulating osmoregulatory substances in leaves and tillering nodes.During this period,the semi lethal temperature gradually decreased,and the semi lethal temperature of White BK-1 reached -9.93 ℃,which was 1.95 ℃ lower than Wintergraze 70 while the soil freezing.The increase of soluble sugar and soluble protein contents in the leaves and tillering nodes of White BK-1 was greater than those of Wintergraze 70,which meant these physiological pathways played an important role in improving the tolerance of White BK-1 to low temperatures in winter.Research on the rejuvenation period found that with the extension of low temperature stress time,the content of malondialdehyde first increased and then decreased.Rye resisted the low temperature of rejuvenation period by increasing the content of osmoregulatory substances,improving the activity of antioxidant enzymes in leaves and regulating the activity of antioxidant enzymes in tillering nodes.White BK-1 suffered less damage under the low temperature stress during rejuvenation period,and its malondialdehyde content was lower than Wintergraze 70 after recovery.In addition,after recovery,two varieties of rye accumulated higher contents of proline and soluble protein in the tillering nodes,which providing sufficient nutrients for growth and development after rejuvenation.

In order to identify the differences in source-sink relationships among different types of barley and the main source-sink indexes affecting yield,four barley materials with large leaf area differences,GP6,GKP7,GK6 and C2-1,were selected to study the differences in photosynthetic characteristics,dry matter,soluble carbohydrates,and filling characteristics and their relationships with yield in 7—28 d after anthesis.The results showed that the length-to-width ratio of flag leaves of GK6 and GKP7 was lower than that of GK6 and C2-1,while the chlorophyll content,photosynthetic rate and soluble sugar of flag leaves and penultimate leaves were higher.The chlorophyll content of flag leaves and penultimate leaves of GKP7 decreased the most,while the decrease of GK6 and C2-1 was smaller.During the early stage of grain filling,the dry weight of leaves and stem sheaths in GK6 was the highest,but the dry matter decreased the most during the filling process.The dry weight of GP6 and GKP7 was lower than that of GK6 and higher than that of C2-1,but the decrease was relatively small throughout the filling period;the grain rapid weight gain time of GP6 and GKP7 was 7—21 d longer than that of GK6 and C2-1(7—14 d),and the average filling rate(R) and time of maximum filling rate(Tmax)of GP6 was the highest,and the soluble sugar content of stem sheath and grain was lower than that of C2-1 at the early filling stage,which was higher than that of other materials.GKP7 filling active periods(D) and maximum filling rate(Rmax)were the highest,soluble sugar content in stem sheath was lower than GP6 and C2-1 at the early grout stage,and higher than other varieties at the later grout stage of leaf and stem sheath.The soluble sugar content in all organs of GK6 was low,and the soluble sugar content in stem sheath and grains was the highest at the early stage of C2-1 filling,but the content decreased rapidly at 7—14 d and was lower at the later stage of filling.The number of thousand grains weight and yield of GK6 and GKP7 were significantly higher than those of GK6 and C2-1,and the sink capacity of GK6 and C2-1 was smaller.Grain weight per spike/leaf area was GKP7>GP6>C2-1>GK6.Correlation analysis showed that the ratio of flag leaf length to width was negatively correlated with yield,and the stem sheath and leaf dry weight,leaf soluble sugar content,number of grains per spike,grain weight per spike/leaf area were positively correlated with yield at maturity.The chlorophyll content and photosynthetic rate at 7 d after anthesis,the grain dry weight at 14—28 d after anthesis,R and Rmax were positively correlated with yield.In summary,GKP7 has the most reasonable source-sink relationship,with GP6 ranking second,C2-1 source and sink are small,and GK6 source is large and sink is small.The ratio of flag leaf length to width,chlorophyll content and photosynthetic rate at the beginning of filling,grain dry weight,maximum filling rate and average filling rate can be used as the main indexes for high yield breeding.

To explore the effects of different farming modes on the growth and development,photosynthesis,leaf structure and yield of maize,and to provide a theoretical basis for optimizing the cultivation measures and creating efficient planting patterns of maize in Hexi oasis irrigation area.Two tillage methods,no-tillage(NT)and conventional tillage(CT),and three planting patterns,wheat-maize intercropping(W/M),winter rapeseed-maize rotation after wheat(W-G→M),and wheat-maize rotation(W-M),were set up in the experiment,with a total of 6 treatments.The results showed that compared with CT,the plant height,stem diameter and leaf area of NT maize increased by 6.83%,4.10% and 3.97%,respectively.The dry matter quality of intercropping maize was higher than that of rotation,but the difference was not significant.The leaf pigments increased first and then decreased with the growth period,which showed that NT chlorophyll a,b and carotenoids were 11.93%,22.41% and 13.43% higher than CT,respectively,and the difference was significant.The net photosynthetic rate(Pn)and intercellular CO₂ concentration(Ci)of NT leaves were 9.17% and 3.81% higher than those of CT.The stomatal conductance(Gs)and transpiration rate(Tr)of CT treatment were 9.95% and 1.48% higher than those of NT.The leaf structure of NT maize was better,the mesophyll cells were more and arranged in order,the vascular bundles were clearly visible,the garland structure was larger,the palisade tissue and sponge tissue were rich,and the leaf thickness of NT was 2.51% thicker than that of CT,and the difference was significant.The yield of NT maize increased by 8.02% compared with CT,and the yield benefit of intercropping was greater than that of rotation(LER>1).This study found that the growth and development,leaf structure and yield of no-tillage maize were better than those of traditional tillage,and wheat intercropping maize could be promoted as the main farming mode in this area.

To study the effect of different color bags on Marselan grape berry quality,and providing high quality raw material for vine culture.A complete randomized experiment design was used to analyze the effects of different color bags on berry quality(external quality and internal quality),peel quality and antioxidant activity.100 berries weight,reducing sugar,titrable acid and pH were increased in bags.The red bag increased the total phenols,total flavan-3-ols and total flavonoids,with 376.03,149.78,1 463.53 mg/kg,respectively,there were significantly differences for the total flavan-3-ols and CK,the total flavonoids and the CK.Blue and yellow bag treatments reduced the total phenols,total flavan-3-olsand total flavonoids.Bagging treatment significantly reduced total tannin content,the total tannin content of yellow bag was the lowest at 4.62 mg/g.Generally speaking,bagging treatment decreased DPPH free radical scavenging ability,FRAP(Reducing ability to Fe²⁺)and ABTS free radical scavenging ability,there was no significant difference for DPPH free radical scavenging ability and FRAP of red bag with CK,yellow bag significantly reduced FRAP,DPPH free radical scavenging ability and ABTS free radical scavenging ability.Correlation analysis showed that the soluble solids were positively correlated with reducing sugar and the sugar/acid ratio,the correlation coefficients were 0.98 and 0.95,respectively.In terms of peel quality,the total phenol was positively correlated with total flavan-3-ols and total flavonoids,the correlation coefficients were 0.95 and 0.98,there was a very significant positive correlation between total flavan-3-ols and total flavonoids,and the correlation coefficient was 0.98.For antioxidant activity,FRAP was very significant positively correlated with DPPH free radical scavenging ability and ABTS free radical scavenging ability free radical scavenging ability,the correlation coefficient were 0.74,0.86,respectively.Soluble solids,reducing sugars and sugar-acid ratio were significantly positively correlated with total anthocyanins,the correlation coefficients were 0.93,0.90 and 0.92,respectively.Principal component analysis was carried out on all the measured indicators,and two principal components with eigenvalues greater than 1 were extracted,the contribution rates of 78.31% and 10.09%,respectively,and cumulative contribution rates of 88.40%,which could basically represent most of the data of quality indicators.Red and blue bags were beneficial to berry quality,and the red bag was better,which can be used in Turpan region.

In order to study the correlation between stem traits and the formation of elasticity and density tolerance of maize,and further reveal the mechanism of lodging resistance,6 maize varieties with different lodging resistance were selected as materials,and 3 planting densities of 6.0×10⁴,7.5×10⁴ and 9.0×10⁴ plants/ha were set.The stem pull lodging angle in the field was used as the evaluation index of elasticity,and the morphological characteristics between plants and basal nodes.The internode anatomical structure,material accumulation and mechanical characteristics were analyzed.The results showed that plant height,ear height,basal internode length,thickness,epidermal thickness,crusty tissue thickness,total vascular bundle,sheath area of small vascular bundle,fresh weight per unit length,dry weight per unit length and content of each component,puncture and folding strength had significant effects on the stem pull lodging angle,among which internode diameter(r=0.521^**)and dry weight per unit length(r=0.562^**)had the greatest effects.The greater the planting density,the smaller the internode diameter,the thickness of the hard skin tissue,the total number of vascular bundles,the fresh weight per unit length,the dry weight,the content of each component,the lodging resistance,the worse the elasticity of the stem.There were significant differences in stem traits among different varieties.The elasticity related traits of Lishou 1,Chuangyu 107,Jingnongke 728 and MC278 were better than those of other varieties,and the variation amplitude was smaller with the increase of density,so the elasticity and density tolerance were stronger.Traits such as internode diameter and dry weight per unit length had significant effects on stem pull lodging angle, that was stalk elasticity,and the variation amplitude of these traits after densification determined the density tolerance of stalk.

Knockout mutants ossaur55-1 and ossaur55-2 obtained by CRISPR/Cas9 technology in Francis background were used as research objects to study whether they affect the changes of agronomic traits such as plant type,leaf color,ear weight per plant and seed setting rate of rice.To explore whether OsSAUR55 regulates rice plant type by participating in GA pathway,and to provide theoretical basis for regulating rice plant type by related hormone pathway.The main agronomic traits of wild type(WT)and knockout mutant in adult plant stage were examined,including plant height,ear length,ear weight per plant,ten grain length,ten grain width,blade length,and blade width.Chlorophyll content and net photosynthetic rate of wild type and mutant leaf were measured by chlorophyll meter and photosynthetic rate meter.Real-time Fluorescence Quantitative PCR(qPCR)was used to determine the expression of OsSAUR55 gene in different tissues and different time points of rice seed germination.The subcellular localization of OsSAUR55 protein was observed by prokaryotic expression method.The contents of endogenous hormones(GA and IAA)in wild type and mutant were determined by liquid chromatography-tandem mass spectrometry(LC-MS/MS).The expression of genes related to GA pathway was further analyzed.In the adult plant stage,mutant ossaur55-1 and ossaur55-2 showed significant phenotypic changes,in which the mutant was significantly shorter in plant height,greener in leaf color,increased in chlorophyll content,decreased in photosynthetic efficiency,decreased in seed setting rate,decreased in 1000-grain weight and decreased in panicle weight per plant than the wild type.The quantitative results showed that OsSAUR55 expression was the highest in the plumule,but not in the flag leaf.Confocal results showed that OsSAUR55 may be localized in cell membrane and nucleus.The results of hormone detection showed that the content of GA₄ was decreased significantly.Gene expression analysis showed that the expression levels of genes KAO,GA13ox1,GA20ox1 and KO1 in the GA synthesis pathway were significantly higher than those of the wild type,and the expression levels of GA2ox5,GA2ox8 and GA2ox9 in the GA metabolic pathway were also significantly higher than those of the wild type.It is preliminarily speculated that the deletion of OsSAUR55 gene led to the decrease of endogenous GA₄ content,which may regulate rice plant type through GA pathway,and then affect rice yield.

To investigate the effect of exogenous melatonin (MT) on salt tolerance of soybean seedlings,and to screen the appropriate application concentration under different salt stress.The soybean variety Tianyou-2986 was used as the test material,and 3 salt concentrations (low salt S₃:3 g/L,medium salt S₅:5 g/L,high salt S₇:7 g/L ) and 6 MT concentrations were set(M₀:0 μmol/L,M₁:25 μmol/L,M₂:50 μmol/L,M₃:75 μmol/L,M₄:100 μmol/L,M₅:150 μmol/L),the morphological parameters,biomass,antioxidant enzyme activity and osmoregulatory substance content of soybean seedlings were analyzed.With the increase of salt stress,the root morphological parameters,biomass,root-shoot ratio,antioxidant enzyme activity and osmoregulatory substance content of soybean seedlings decreased,while the malondialdehyde content increased.Under low salt (S₃) and medium salt (S₅) stress,The number of total length,lateral roots,SOD and POD of 50 μmol/L MT were increased by 52.30%,19.98%,74.10%,40.03% (low salt) and 68.52%,19.24%,81.72% and 37.42% (medium salt),respectively.Under high stress (S₇),75 μmol/L MT increased by 71.17%,19.11%,80.79% and 27.01%,respectively.Under salt stress,exogenous 25—100 μmol/L MT promoted soybean seedling growth and improved salt tolerance to different degrees.The overall evaluation of the affiliation function showed that 50 μmol/L MT was the most effective in alleviating salt damage under low and medium salt stress,and the suitable concentration of MT was 75 μmol/L under high salt stress,and the main reason for the alleviation of salt damage in soybean seedlings was that MT increased the activities of antioxidant enzymes and osmoregulatory substance content,and reduced the content of malondialdehyde,which could alleviate oxidative and osmotic stresses of soybeans under salt stress.

To clarify the effects of drought stress and cultivars on the net photosynthetic rate(Pn),the activities of photosynthetic enzymes in flag leaf in the afternoon(FLA)during grain filling stage and grain yield of winter wheat,a pond culture experiment with four water levels and two winter wheat cultivars was conducted under the condition of rainproof pond cultivation in 2019—2021.The four water treatments included severe drought(W1),moderate drought(W2),mild drought(W3),and suitable water supply(W4).The Pn,and the activities of Rubisco,RCA,PEPC,ATPase and PPDK in flag leaf from 14:00 to 16:00 during the early(EGFS)and medium(MGFS)grain filling stage,and the grain yield at maturity of strong drought resistance cultivar Jinmai 47(JM47)and weak drought resistance cultivar Yanzhan 4110(YZ4110)were investigated.Drought stress decreased the FLA Pn and activities of most photosynthetic enzymes,and the grain yield of wheat.The decrease of these indexes increased with drought stress degree,but the effects were different among varieties and years.Compared with W4,the FLA Pn of JM47 under W1,W2 and W3 decreased by 33.6%—40.6%,12.0%—30.5% and 5.0%—13.5%,as well as YZ4110 decreased by 44.0%—52.0%,22.5%—38.1% and 11.5%—20.5%,respectively.Compared with W4,the FLA Rubisco activity decreased during EGFS but increased during MGFS for JM47,while it decreased by 13.3%—25.6%,7.1%—14.0% and 11.2%—11.6% for YZ4110,respectively,under W1,W2 and W3.Compared with W4,the FLA RCA activity significantly decreased under most drought treatments during EGFS,while increased under W2 and W3 for JM47 and decreased under W1 and W2 for YZ4110 during MGFS.Compared with W4,the FLA ATPase activity of JM47decreased under W1 but increased under W3,while that of YZ4110 decreased under W1,W2 and W3 by 19.3%—48.7%,7.2%—24.2% and 0.1%—8.9%,respectively.The FLA PEPC activity under different treatments varied with growing seasons and varieties.Compared with W4,the FLA PPDK activities of JM47 and YZ4110 under W1 were decreased by 12.4%—18.8% and 16.7%—18.2%.Compared with YZ4110,in most conditions,the FLA Pn and photosynthetic enzyme activities of JM47 had no significant difference under suitable water supply(W4),but increased under drought treatments(W1,W2 and W3).The results of correlation analysis showed that yield,FLA Pn were significantly positively correlated to FLA ATPase activity during EGFS and MGFS,as well as FLA PEPC activity during EGFS.Thus,increasing the FLA ATPase and PEPC activities during the grain filling period is conducive to the increase of FLA Pn and grain yield of wheat.

Fruit development is the key stage which determines the yield and quality of grape.WRKY family transcription factors play important roles in regulating plant development and environment adaptation.Ethylene is the important plant hormone which participates in regulation of fruit development,and ACC synthase is the key enzyme that limits ethylene synthesis.Using grape variety Zuoyouhong, VvWRKY13 overexpressing grape callus,as well as VvWRKY13 heterologous over-expressed tomato lines as materials,the role of VvWRKY13 from grape in fruit development and its relationship with ethylene were studied though plant physiological and biochemical methods as well as molecular biological techniques.The results displayed that the expressions of VvWRKY13 as well as ACC synthase genes VvACS2 and VvACS7 significantly upregulated at early stage of fruit development,and in VvWRKY13 over-expression grape callus,the expression of VvACS7C was significantly higher than control,but the expression of VvACS2 displayed no significant difference compared with control.Yeast one hybrid experiment showed that VvWRKY13 could directly bind to the VvACS7 promoter,VvWRKY13 had no direct interaction with VvACS2.We also found that the ethylene content and the expression of ACS family members,such as SlACS1b,SlACS4 and SlACS6,the ethylene synthesis genes,were significantly induced in VvWRKY13 heterologous over-expressed tomato,and the time from flowering to breaking of tomato was 3—6 days shorter than wild type;the above results indicated that,VvWRKY13 could regulate ethylene synthesis by promoting the expression of ACC synthase gene to participate in regulation of fruit development.

In order to investigate the effect of chitooligosaccharides (COS) on the growth of kale sprouts and to provide a reference for the rational application of chitooligosaccharides in the production of sprouts,this study used Jingyu 1 as the test material,and applied different concentrations of COS (25,50,75,100 mg/L) to the seeds after germination to observe the effects of COS on the growth indexes,content of glucosinolates and antioxidant capacity.The results showed that total phenolics content,total flavonoids content,total glucosinolates content,myrosinase enzyme activity and DPPH free radicals scavenging rate of 75 mg/L COS-treated kale sprouts showed an upward trend,and the differences were significant with the control,with increases of 25.99%,17.99%,29.68%,141.88%,and 2.51%,respectively;the yield and total phenolics content,total flavonoids content,sodium content,boron content and myrosinase enzyme activity,of 100 mg/L COS-treated kale sprouts were also enhanced accordingly and differed significantly from the control,increasing by 15.21%,21.29%,22.47%,15.97%,32.63%,97.71%,respectively.After correlation analysis,it could be obtained that the yield of sprouted seedlings was significantly and positively correlated with the content of carotenoids,total phenolics,and total flavonoids and DPPH free radicals scavenging rate.In conclusion,chitosan treatment could increase the yield of kale sprouts,improve the nutritional quality and antioxidant capacity of sprouts,and increase the edible value of sprouts.

To investigate the effects of Piriformospora indica combined with Arbuscular mycorrhizal fungi (AMF) on drought resistance of tobacco,Yunyan 87 was inoculated with sterile water (CC),P.indica (CP),AMF (PC),P.indica and AMF (PP),and the contents of proline (Pro),superoxide dismutase (SOD),peroxidase (POD),malondialdehyde (MDA) and the expression of drought-related genes NTNAC1 and NAC4 in tobacco leaves were determined under stress in the form of natural drought.The results showed that P.indica and AMF could promote the growth of above-ground and underground parts of tobacco,and chlorosis of leaves and symptoms of their drought were slight.After 7 days of drought stress,the contents of Pro in tobacco leaves of CP,PC and PP groups were 1.39,1.59 and 1.78 times higher than those of CC in group,respectively.The activities of SOD and POD in tobacco leaves increased first and then decreased.The activities of SOD in CP,PC and PP groups were 1.15,1.22 and 1.33 times higher than those in CC group,POD activity was 1.33,1.46 and 1.85 times higher than those of CC group,respectively.The content of MDA in tobacco leaves was decreased by 21.98%,23.98% and 24.84% in CP,PC and PP groups respectively.The expression levels of NTNAC1 and NAC4 in tobacco leaves were up-regulated.The expression levels of NTNAC1 in CP,PC and PP groups were 3.37,3.88 and 5.07 times higher than those in CC group,the expression levels of NAC4 gene were 3.04,3.59 and 5.56 times higher than those of CC group,respectively.This study indicates that P.indica and AMF showed significant synergistic effects,which could significantly improve the drought resistance of tobacco.

To explore the physiological response mechanism of maize to different drip irrigation quotas,a 2-year pond planting experiment was conducted under controlled conditions.Using two maize varieties with differences in drought resistance as materials,six treatments were set up:CK1 (Drought resistant variety,500 mm),T1 (Drought resistant variety,350 mm),T2 (Drought resistant variety,200 mm),CK2 (Drought sensitive variety,500 mm),T3 (Drought sensitive variety,350 mm),and T4 (Drought sensitive variety,200 mm) to analyse the photosynthetic,chlorophyll fluorescence,photosynthetic response characteristics,and grain filling characteristics of maize leaves changed in hormone content,starch synthase activity,and yield in grains.The results showed that four photosynthetic parameters,including net photosynthetic rate (Pn),and four chlorophyll fluorescence parameters,including maximum photochemical quantum yield of photosystem Ⅱ (Fv/Fm),decreased with the decrease of drip irrigation quota,while stomatal limitation percentage (Ls) and non-photochemical quenching coefficient (NPQ) increased.The apparent quantum efficiency (AQE) and other 10 photosynthetic response related parameters of maize leaves all decreased with the decrease of drip irrigation quota.The range of differences between light compensation point (LCP) and light saturation point (LSP),CO₂ compensation point (CCP) and CO₂ saturation point (CSP) in CK1,T1,and CK2 treatments was larger than that in other treatments.The grain filling rate reached its peak at 25 d after anthesis,and the T2,and T4 treatments significantly decreased compared to the CK1 and CK2 treatments.The content of cytokinin (CTK) and auxin (IAA) in grains decreased with the decrease of drip irrigation quota,and the content of abscisic acid (ABA) increased.The activities of acid sucrose invertase,sucrose synthase,starch synthase and adenosine diphosphate glucose pyrophosphorylase in grains of T2 and T4 treatments were significantly lower than those of CK1 and CK2 treatments.The maize yield significantly decreased with the decrease of drip irrigation quota,and the T1 treatment only decreased by 3.45% to 4.51% compared to the CK1 treatment.There was no significant difference between T1 treatment and CK1 and CK2 treatment in the above indicators.The leaves of maize treated with T1 treatment still maintained the photosynthetic performance and photosystem Ⅱ structure,enhanced the adaptability of leaves to light and CO₂,increased the content of hormones related to maize grains and the activity of enzymes related to starch synthesis,effectively regulated the growth and development of maize grains and the filling process,and maize yield and its components performed better.

In order to explore the effect of salt stress on the physiological mechanism of cotton,saline-tolerant cotton Zhong J0710 was used as a control,two new cotton distantly hybrid germplasms HL2 and A₂H cultivated in cotton breeding research group were treated with salt solution for 15 d(concentration of 200 mmol/L)at seedling stage,and the relative plant height,relative root length and relative survival rate of the test materials were analyzed,and the salt damage index was calculated.The salt tolerance of the test materials was comprehensively evaluated by combining the measurement results of physiological indicators such as primary light energy conversion efficiency (Fv/Fm),antioxidant enzyme activity,proline content,and soluble sugar of seedlings at different treatment times (0,5,12,24,48 h).The results showed that after 15 d of salt stress,the damage degree of the growth of seedlings of the three test materials was as follows:Zhong J0710<HL2<A₂H,and salt stress significantly inhibited the relative plant height,relative root length and relative survival rate of A₂H,indicating that the salt concentration treatment had less effect on the growth and development of HL2 and Zhong J0710,but had a greater effect on A₂H.Under different treatment times,salt stress had different degrees of influence on the maximum light energy conversion efficiency of the three test materials,and the inhibition degrees from weak to strong compared with before stress were HL2<A₂H<Zhong J0710.Compared with the non-stress period, the peroxidase (POD) activity of the tested materials was increased by salt stress, and the POD activity of HL2 during the stress process was significantly higher than that of A2H and Zhong J0710 in the salt-tolerant control, and reached a very significant level at 12—48 h of stress,and the change law of superoxide dismutase (SOD) activity was not obvious,and the role in salt stress was low.The contents of proline in HL2 and the salt-tolerant control increased with the increase of salt stress time,and the soluble sugars and soluble proteins of germplasm HL2 were significantly higher than those in the salt-tolerant control and A₂H during the entire salt stress period.In summary,in salt adversity,salt-tolerant materials have a more developed root system;higher light energy conversion efficiency,higher reactive oxygen species clearance capacity in cells and higher accumulation of osmoregulatory substances are the physiological basis for strong salt tolerance.

To clarify the impacts of flooding stress on the morphological structure and activities in different types of roots for maize at seedling,two typical maize cultivars Zhengdan 958(ZD958,a tolerant genotype)and Liyu 16(LY16,a susceptible one)were selected,and five flooding durations at three leaf stage were established:0(CK),2,4,6,8 d,to explore the response law involving morphology and root activities of embryonic and adventitious root to excessive moisture.The results showed that after 2 days of flooding,the root length,root surface area,root volume,root tip number and root fork number of primary root,seminal root and adventitious root in maize were significantly higher than those of CK.With the extension of flooding duration,these indexes decreased obviously,but the average root diameter displayed an outstanding enhancement.Compared with CK,the morphological indexes of emerging adventitious root under flooding performed better,and among them,the root length and root tip number suffered the most from flooding.The total number,the layer number and the angle of adventitious root increased after flooding.With the elongation of flooding duration,except dry weight at the first layer of adventitious root,the primary root,seminal root and secondary layer of adventitious root of ZD958 increased first and then decreased,but those of LY16 decreased from the start.The root-shoot ratio rose from 2 days to 6 days,and then declined after that.The root activities of primary root and seminal root were significantly reduced under flooding,however,the function of adventitious root could be maintained for 4—6 days.It is concluded that the negative effects of flooding on different root types indicated primary root>seminal root>adventitious root,and response features were different from both varieties.In addition,the adventitious root activity and root-shoot ratio of flooding resistant variety begin to decrease after 8 days of flooding.

In order to screen chemical control agents that can effectively reduce millet plant height and improve its lodging resistance,as well as the optimal spraying period,and explore the effects of different chemical control agents on millet growth,development,and yield,four chemical control agents (paclobutrazol,Menthylamine,cynanchon,and uniconazole)were sprayed on Nenxuan 17 during the seedling and jointing stages.The dry matter accumulation, SPAD, net photosynthetic rate, stem characteristics and yield components of each treatment plant were measured during the filling and mature stages.The results showed that spraying uniconazole,chlorpyrifos,chlorpyrifos,and paclobutrazol during the seedling and jointing stages of foxtail millet could dwarf plants to varying degrees,increase stem diameter,improve lodging resistance,and achieve yield increase.Among them,the plant height and internode length of foxtail millet decreased by 6.76% and 25.43% respectively compared to CK during the seedling stage.Spraying chloramphenicol had the most significant effect on increasing stem diameter during the seedling stage,which was 22.89% higher than CK.The foxtail millet had the best lodging resistance under the spraying of foxtail millet,and the spraying of foxtail millet had the most significant effect on increasing yield during the seedling stage,which was 17.51% higher than CK;all four regulators could significantly increase the SPAD value and net photosynthetic rate of millet leaves.Spraying paclobutrazol at the seedling stage had the best effect on improving the SPAD value and net photosynthetic rate,with an increase of 35.29% and 30.37% respectively compared to CK;spraying chemical control agents had no significant effect on the accumulation of aboveground dry matter in millet plants compared to CK.Overall,spraying paclobutrazol during the seedling stage had the best effect and could be applied as a suitable chemical control and lodging resistance measure for high-yield cultivation of millet.

To clarify the effects of soybean staygreen syndrome on the yield.Different treatments were set up for the main hazard factors that cause soybean staygreen syndrome disease,the resistance of 65 soybean varieties was screened and identified,and the synergistic effect of different hazard factors was analyzed. The results showed that the resistance of different soybean varieties to soybean hazard factors was different,and the number of T2 treated soybean staygreen syndrome sensitive varieties was the smallest,with 53,accounting for 81.54%. The number of soybean staygreen syndrome sensitive varieties of T4 was the largest,with 58,accounting for 89.23% of the total. Compared to the changing range of the control,the average rate of soybean staygreen syndrome with T4 and T5 composite hazard factors (263.87%—281.57%)was larger than that of individual hazard factors (117.82%—151.58%). The effects of treatment of different hazard factors on the main agronomic traits of soybean have reached a significant level. Compared with the control,among the seven major agronomic traits,the 5 treatments of the node numbers of main stem had the smallest change range,with an average of decreasing range 7.71%,and the number of staygreen syndrome pods per plant had the largest change range,with an average of amplification 83.52%. Among the three yield related traits,the 5 treatments with 100 seed weight had the smallest loss rate compared with the control,with an average of decreasing range 8.70%,and the 5 treatments with seed weight per plant had the largest loss rate with an average of decreasing range 52.51%. In short,the results revealed that the effects of treatment of different hazard factors on the yield and main agronomic traits of soybean have reached a significant level,and the seed weight per plant had the largest change compared with the control.

Brassica napus has the potential to tolerate Cadmium(Cd)pollution while producing safely.To provide theoretical support for the ecological restoration and safe utilization of Cd-polluted farmland using B.napus,field plot experiments involved 24 widely grown winter rape varieties were performed in October 2020 at the Agricultural Science Research Institute in Xiangtan City,Hunan Province.Cd accumulation in different tissues of the rape plants grown in low-concentration Cd-polluted farmland(total Cd content 0.54 mg/kg,effective Cd content 0.23 mg/kg)was analyzed.Effective Cd content did not differ significantly among different plots,while there were differences in Cd absorption and accumulation in different tissues of mature rape plants.The highest average Cd content was observed in leaves,followed by roots,stems,and silique walls,while the lowest value was in seeds,which was below the national food pollutant standard(0.1 mg/kg).There was no significant difference in Cd content in roots of different rape varieties,but there were differences in stems,branches,silique walls,and seeds.The transmission coefficients in different tissues of different rape varieties were analyzed,and the results showed that there were differences in transfer coefficients between different varieties.In Qingyou 1,the transmission coefficients in leaves and silique walls were relatively high,but low in seeds.Fengyou 737 and Yangyou 9 had higher transmission coefficients in branches and leaves,and medium values in seeds.The total Cd content in the harvested parts of rape plants was analyzed,and the results indicated that varieties such as Huaza 62 and Qingyou 1 had high total Cd content but low Cd content in seeds.In conclusion,B.napus has the ability to enrich Cd,and varieties such as Huaza 62 and Qingyou 1 have the potential to restore slightly Cd-polluted farmland while ensuring production safety.

In order to have a clearer understanding of the research progress on cold resistance of winter rapeseed in cold and arid regions of China,and to provide theoretical support for breeding and production.The research progress of cold-resistance and cold-resistance breeding of winter rapeseed were summarized respectively from six aspects such as selection index and method,genetic law,breeding method,screening effect,germplasm classification and molecular mechanism research,and four aspects such as breeding method,breeding varieties,cold resistance classification and adaptability screening of varieties.Based on the analysis of the existing problems,six measures were put forward,such as creating germplasm resources by multiple ways,screening out core germplasm by comprehensive evaluation,carrying out research on cold-resistance mechanism and construction of innovation system of molecular design breeding,constructing breeding system and carrying out cold-resistance breeding by multiple ways,improving the adaptability of varieties by comprehensive screening,promoting varieties yield level and improving benefits by carrying out matching cultivation techniques,in order to promote the development of rapeseed production in cold and arid regions of our country.

In order to cultivate and screen saline-alkali tolerant peanut varieties and expand the utilization area of saline-alkali soil,50 peanut varieties were used as materials,and four saline-alkali gradients,including 0,0.4%,0.8% and 1.2%,were set by potting to screen saline-alkali tolerant varieties. The results showed that under the saline-alkali stress of 0.8% in the germination stage,the seeds of 50 varieties were significantly differentiated in terms of saline-alkali tolerance,and the germination rate and seedling vigor of 8 varieties remained above 90% and 85%. The evaluation results of various physiological indexes at the seedling stage showed that the root indexes and aerial traits did not change much under low concentration (0.4%)saline-alkali stress,but showed different degrees of decline under medium (0.8%)and high (1.2%)concentration stress,and the reduction range was 22%—54% and 30%—56%,respectively. In addition,chlorophyll indexes showed an upward trend with the increase of saline-alkali concentration,with an increase range of 12%—13%. The comprehensive evaluation results of peanut using the excellent index showed that 23,5 and 0 varieties performed excellently under the saline-alkali stress of 0.4%,0.8% and 1.2%,respectively. Correlation analysis revealed that,there was no significant correlation between saline-alkali tolerance stress at the germination stage and the seedling stage,indicating that there were different mechanisms of saline-alkali tolerance during germination and seedling stages. The above results concluded that under the conditions of pot cultivation,moderate concentration (0.8%)saline-alkali was suitable for the screening of peanut saline-alkali tolerance varieties. According to the comprehensive excellence index,five saline-alkali tolerant peanut varieties were selected,namely Jihua 572,Tang 3432,Jinonghua 31,Yihua 16 and Yuhua 191,which provided a basis and germplasm resources for the promotion and cultivation of salt alkali tolerant peanut varieties.

To explore the relationship between agronomic traits and yield of oil sunflowers and select new high-quality and high-yield oil sunflower varieties suitable for climate and planting mode of Hebei Province,genetic diversity analysis,correlation analysis,systematic cluster analysis,and principal component analysis(PCA)were conducted on 14 traits of 39 oil sunflower hybrids.The research results indicated that the coefficient of variation for different traits ranged from 2.50% to 32.37%.Among them,the coefficient of variation of grain weight per head was the highest,at 32.37%,with a variation range of 16.77—113.78 g.The coefficient of variation during the growth period was the smallest,only 2.50%.The yield was extremely significantly positively correlated with 100-grain weight,grain number per head,grain weight per head,grain volume weight,and plant height,and significantly positively correlated with grain area,grain circumference,and grain length;Plant height was extremely significantly positively correlated with 100-grain weight,grain area,grain circumference,grain length,grain width,and grain volume weight,and significantly positively correlated with grain weight per head.PCA divides the agronomic traits of different varieties into four principal components,which could be summarized as grain trait factors,yield factors,growth period and morphology factors,and grain volume weight factors,with a cumulative contribution rate of 81.939%.At a Chi-square distance of 1.05,39 materials were divided into 4 groups,among which group Ⅰ contained 23 materials with excellent grain and yield traits,and was similar to the characteristics of group Ⅰ in the PCA scatter diagram.Based on the above data analysis,from the perspective of selection potential,the impact of traits such as grain weight per head,grain number per head,head diameter,plant height,and 100-grain weight on yield should be mainly considered.

It was carried out to understand the effect of different light spectrum on the growth and quality of Helianthus annuus sprouts in artificial light plant factory.Green light(B+G),red light(B+R),far red light(B+Fr)and ultraviolet light(B+UV)with the same light intensity were added on the basis of blue light with the light intensity of 200 μmol/(m²·s).Blue LED was taken as the control.The results showed that the hypocotyl length of Helianthus annuus sprouts under B+Fr treatment increased significantly compared with the control.B+R treatment greatly improved the hypocotyl diameter,root length and fresh and dry weight of Helianthus annuus sprouts.Light quality treatments also affected the quality indexes of Helianthus annuus sprouts.Compared with the control,the content of soluble sugar,soluble protein and flavonoids of Helianthus annuus sprouts under B+G treatment increased significantly,increased by 28.78%,72.65% and 163.32% respectively.B+UV treatment significantly increased the content of total phenol,vitamin C,chlorophyll a and carotenoid by 25.81%,238.10%,12.50% and 150.00%,respectively.B+Fr treatment was beneficial to increase the content of volatile aromatic substances in Helianthus annuus sprouts,such as C₆H₁₀O,C₁₀H₁₆ and C₁₀H₁₄.In conclusion,B+R promotes the growth of Helianthus annuus sprouts,while B+G light improves the quality of Helianthus annuus sprouts.

The cultivation of salt-tolerant varieties is one of the measures to improve the yield reduction caused by secondary salinization. Therefore,the salt-tolerant varieties were screened and their tolerance mechanism were determined.Under control and salt treatment conditions,9 varieties of Brassica Campestris L. were used to compare the differences of salt-tolerance among varieties. Meanwhile,the salt-tolerant varieties and salt-sensitive varieties of Brassica Campestris L. were screened out. The photosynthetic characteristics,MDA content,relative conductivity,histochemical staining,SOD,POD,CAT,APX activity,root activity,nitrate content,and nitrate reductase activity of different varieties were determined under salt stress condition. Finally,the salt tolerance mechanism was preliminarily clarified.The growth indexes of 9 varieties were analyzed,and the salt-tolerant variety Lianzhou F₁ and salt-sensitive variety Jinqiuhong No.2 were selected. Compared with 15 mmol/L Ca(NO₃)₂ treatment (the control),the chlorophyll content,net photosynthetic rate,stomatal conductance,and transpiration rate of Lianzhou F₁ under 80 mmol/L Ca(NO₃)₂ stress were significantly lower than those of Jinqiuhong No.2. The relative conductivity,MDA content,O₂ {\mathrm{ }}^{\frac{-}{·}},and H₂O₂ content of Lianzhou F₁ had a slower degree of increasing than those of Jinqiuhong No.2 under Ca(NO₃)₂ stress,while the scavenging of oxygen free radicals had an opposite trend. Compared with the control,the increase of nitrate content in the shoot and root of Lianzhou F₁ under 80 mmol/L Ca(NO₃)₂ stress was lower than that of Jinqiuhong No.2,while the activity of nitrate reductase showed an opposite trend. Moreover,the root activity of Lianzhou F₁ was less affected by nitrate than Jinqiuhong No.2.Lianzhou F₁ is a salt-tolerant Brassica Campestris L. variety,and Jinqiuhong No.2 is a salt-sensitive variety. Lianzhou F₁ has a low degree of oxidative stress,and a high photosynthetic efficiency and nitrate reducing ability,which can make it have a good growth ability under nitrate stress. Therefore,in the land with high degree of salinization,Lianzhou F₁ was recommended as the main cultivar.

In order to investigate the physiological stress response mechanism of pepper fruits to UV-B radiation and further elaborate the mechanism of fruit quality deterioration in vegetables in high UV-B radiation areas,the young fruits,green fruits and red fruits of UV-sensitive variety Huamei 105 and UV-resistant variety Ledu long pepper were selected as test materials. The effects of different UV-B radiation duration (dose)of 0 (CK),2,4 and 6 h on fruit growth and development,prototype protection and nutrient quality related substances content were studied. The results showed that with the extension of radiation time,the single fruit weight and transverse diameter of Huamei 105 decreased significantly at the green and red fruit stages,which inhibited the fruit growth. The contents of protective substances Vc and total phenol in fruits of the two varieties at each growth stage increased gradually as the extension of treatment time,while the contents of soluble protein decreased gradually. The contents of Vc and total phenol significantly increased after 6 h,and the contents of soluble protein decreased the most. The contents of Vc,total phenol and soluble protein of Huamei 105 changed greater than those of Ledu long pepper. With the extension of radiation time,the content of soluble sugar showed a trend of first increasing and then decreasing,while the content of cellulose showed a trend of first decreasing and then increasing. In conclusion,UV-B had little effect on the indexes in the young fruit stage of the two varieties. High-dose UV-B could significantly inhibit the growth of the UV-sensitive varieties at the green and red fruit stages,and significantly increase the contents of Vc,total phenol,cellulose and other substances in the two varieties,and significantly reduce the contents of soluble protein and soluble sugar. However,low dose UV-B could significantly increase the soluble sugar content,and the increase or decrease amplitude was higher in UV-sensitive varieties than in UV-resistant varieties. Therefore,lower than 1/4 lethal dose of UV-B can promote fruit quality,and higher than 1/2 lethal dose of UV-B can make pepper fruit quality start to deteriorate.

In order to explore the effects of different concentration of exogenous GABA on tomato seedlings dry matter accumulation,root development,antioxidant enzyme activities and photosynthetic characteristics under high temperature stress,the tomato variety Fenteli was selected as the test material,and five treatments,including spraying distilled water (CK),1 mmol/L GABA(T1),5 mmol/L GABA(T2),10 mmol/L GABA(T3)and 20 mmol/L GABA (T4),were set up in this study. Spraying once every two days for two consecutive times. After spraying,the seedlings were exposed to high temperature stress at 40 ℃/35 ℃ (day/night),14 h (light)/10 h (dark)with light intensity of 250 μmol/(m²·s)for 7 days. The results showed that compared with CK,spraying GABA with the concentration of 10 mmol/L or less (T1,T2 and T3)significantly promoted the growth of tomato seedlings,and the plant height,stem thickness,aboveground dry weight and seedling index increased by 4.96%—6.92%,7.65%—19.26%,29.41%—52.94%,20.00%—26.67%,respectively. Noteworthy,compared with CK,T2 treatment significantly increased the total root length,total surface area,total volume and tip numbers of root system by 23.04%,13.95%,11.76% and 18.30%,respectively. Moreover,compared with CK,T2 treatment not only increased the leaves activities of SOD,POD and CAT in (increasing by 22.58%,51.73% and 148.80% respectively),but also decreased the relative conductivity and malondialdehyde content (decreasing by 12.84% and 21.89%),and thus significantly increasing the photosynthetic rate,stomatal conductance and transpiration rate of leaves (increasing by 81.38%,36.19% and 41.26% respectively)by ensuring the integrity of the cell membrane structure and function of leaves. However,there were no significance differences for the dry matter accumulation,photosynthetic characteristics and relative conductivity of tomato seedlings under T4 and CK treatments,and even the former inhibited the root development. In a word,our study demonstrated that foliar spraying with an appropriate GABA concentration could alleviate the inhibition of photosynthesis under high temperature stress through protecting the integrity of leaf cell membrane by improving capacity of leaf osmotic adjustment and antioxidant enzyme activities. Additionally,spraying GABA could also improve the heat tolerance of tomato seedlings by promoting dry matter accumulation and root development. The effect of GABA with 5 mmol/L was the best in this study.

To clarify the optimal harvesting period and storage temperature for the Venus apple fruit used for storage.The effects of three harvesting periods combined with three precise storage temperatures on fruit quality,anti-browning and preservation of Venus gold apple during 20 ℃ shelf life after cold storage were studied. The results showed that harvesting period Ⅰ(relatively early harvest)combined with storage at-1.5 ℃ (relatively low temperature)could maintain high fruit firmness,but the soluble solid content (SSC)of fruit was low,the taste and flavor of fruit were poor,and different degrees of browning of skin,heart and flesh appeared during shelf life. When harvested at period Ⅲ (relatively late),stored at 3 ℃ (relatively high temperature)until January 20,the fruit had high SSC,good taste and flavor. However,when stored at 20 ℃ for 24 h and stored on the shelf for 7 days,the fruit flesh was spongy and severely browning. The results showed that compared with-1.5 and 3.0 ℃,0 ℃ maintained higher firmness,SSC,titratable acid (TA)and ascorbic acid contents,and better maintained fruit chlorophyll fluorescence activity,and delayed fruit senescence. For the same storage temperature,the contents of TA and ascorbic acid in the fruits of harvest period Ⅱ were higher than those of harvest period Ⅰ and Ⅲ. The comprehensive analysis showed that the harvest period Ⅱ and Ⅲ combined with 0,3 ℃ could maintain the good merchantability and intrinsic quality of Venus gold apple stored in the medium and short term. For the Venus gold apple with medium and long-term storage,the harvest period Ⅱ combined with 0 ℃ accurate temperature storage could not only effectively inhibit fruit browning,slow fruit softening and senescence,but also maintain good flavor and quality of fruit during shelf life.