Based on quantitative trait locus(QTL)mapping of grain weight and grain shape-related traits in a backcross inbred line(BIL)population derived from the cross between indica rice variety Changhui 891 and japonica rice variety 02428,this study provided valuable genetic resources for elucidating the genetic basis of grain development and molecular breeding for high yield and quality in rice.A high-density genetic map was used to conduct QTL analysis for thousand-grain weight,grain length,grain width,grain thickness,and length-width ratio under two environments.Transcriptome data of developing grains at 5,10,and 15 days after flowering from both parents were integrated to analyze candidate genes within QTL regions.Frequency distribution indicated that grain weight and shape traits in the BIL population exhibited typical quantitative characteristics,confirming the suitability for QTL mapping.A total of 37 QTLs were detected across both environments,including 18 specific to Hainan(Sanya),12 specific to Jiangxi(Nanchang),and 7 consistently identified in both locations.These QTLs were distributed on chromosomes 1—5,7,8,11,and 12,comprising 7 for thousand grains weight,5 for grain length,7 for grain width,11 for length-width ratio,and 7 for grain thickness.The analysis showed that the LOD values of these QTLs ranged from 2.79 to 43.10,with a contribution rate of 1.36% to 46.12%.By integrating differentially expressed genes from developing grains of both parents at three stages,28 candidate genes were prioritized from the 37 QTL regions.Among these,LOC_Os11g10480 and LOC_Os11g10100 were identified as key candidates for further functional validation.

The screening of aromatic rice germplasm resources and the rapid identification and utilization of aromatic genes have practical significance for the genetic breeding of aromatic rice.In order to clarify the aroma types of aromatic rice materials in Heilongjiang Province and improve the breeding efficiency of aromatic rice varieties,180 aromatic rice varieties approved and promoted in Heilongjiang Province were sequenced.Compared with the reference genome Nipponbare,the sequencing results were divided into two types of mutations.The first type was the 8 bp deletion of exon 7 and three base substitutions(Badh2-E7 type),including 177 varieties.The second type was the 7 bp deletion of exon 2(Badh2-E2 type),which contained only three varieties.According to these two mutation types,two specific KASP molecular markers were designed to accurately detect the aroma types of E7 and E2 in rice.Through the identification of 180 aromatic rice varieties,the typing results were consistent with the sequencing results.Two hybrid populations were constructed by using E7 aromatic rice variety Wuyoudao 4 and E2 aromatic rice variety Songkejing 134 with non-aromatic japonica rice varieties Weinong 101 and Dongfu 114,respectively.The F₂ generation of the hybrid population was screened and identified for aroma genes,and the identification results were consistent with 100%,which verified the accuracy of KASP molecular markers.The 620 japonica rice parents created and collected by our laboratory were further identified by KASP markers,and 248 aromatic rice materials were screened.It was found that these parents were all Badh2-E7 type genes.At the same time,the existing 1 220 F₇ generation materials with E7 aromatic rice as parents were genotyped,including 293 aromatic rice materials,906 non-aromatic rice materials and 21 heterozygous rice materials.Five aromatic and non-aromatic rice materials were randomly selected for sequencing verification.The sequencing results verified that the KASP molecular marker typing was correct.This study provided new markers and materials for breeding new fragrant rice varieties in cold regions by using molecular marker assisted selection.

This study aimed to investigate the effects of acidic soil on the growth metabolism and photosynthesis of Hainan green sweet orange (Citrus sinensis L.)and to elucidate its antioxidant regulatory mechanisms under acid stress.A pot experiment was conducted to analyze the physiological metabolic changes,antioxidant responses,and expression patterns of key antioxidant enzyme regulatory genes in green sweet orange under acid stress.The results showed that the plant height growth,leaf area and fresh weight of green sweet orange plants decreased significantly under a strongly acidic soil environment,with the most serious effect of pH 3.5 treatment;the weakly acidic(pH 6.5)soil could promote the growth of plants,which manifested as positive growth in the amount of each growth index.Strong acid treatment significantly impaired photosynthesis and normal growth metabolism of green sweet orange leaves,manifested as negative growth in transpiration rate(Tr)and stomatal conductance(Gs)were significantly reduced.Superoxide dismutase(SOD)and phenylalanine ammonia-lyase(PAL)activities increased by 6.60-fold and 5.90-fold at 24 h post-treatment under pH 3.5.The malondialdehyde(MDA)content in leaves treated with pH 3.5 increased by 6.47-fold compared to the initial time point(0 h),significantly higher than that under pH 6.5.Principal component analysis(PCA)and redundancy analysis(RDA)revealed a significant negative correlation between enzyme activity and physiological-biochemical indices(R²=0.82).Gene expression analysis demonstrated that CsSOD and CsPAL reached peak levels at 24,48 h post-stress respectively and remained upregulated within 72 h,showing 2.33-fold and 2.64-fold increases compared to 0 h,respectively.In summary,strongly acidic soil inhibits the growth and development of green sweet orange by reducing photosynthetic pigment content and metabolic efficiency.SOD and PAL serve as key antioxidant enzymes in response to acid stress,with CsSOD and CsPAL genes dynamically regulating enzymatic activity to mitigate stress.

To identify the suitable sowing date and planting density for the synergistic improvement of yield and quality of strong gluten wheat,the strong gluten wheat variety Kexing 3302 was used as the experimental material.Two sowing dates(October 18(S1)and October 28(S2))and five densities(basic seedlings of 180×10⁴ plants/ha(D180),225×10⁴ plants/ha(D225),270×10⁴ plants/ha(D270),315×10⁴ plants/ha(D315),and 375×10⁴ plants/ha(D375))were set.Field experiments were conducted in 2021—2023 to investigate the effects of sowing date and density on physiological indicators,yield,and quality of wheat plants.The results showed that the relative chlorophyll content(SPAD)of wheat leaves generally decreased with the increase of planting density,and reached its maximum at most growth stages under low-density treatment.With the delay of the sowing date,the relative chlorophyll content of leaves showed an upward trend,with S1 sowing date being lower than S2.As planting density increased,the normalized difference vegetation index(NDVI)generally showed an upward trend,and the NDVI value at S2 sowing date was significantly lower than that at S1 sowing date.The number of spikes and grain yield decreased with the delay of the planting density,but increased with the increase of planting density,with the highest yield under D375 treatment.With the delay of the sowing date,both protein content and wet gluten content generally showed a slight downward trend,but the grain protein content of all treatments was above 13.5%.The total starch content of wheat grains generally decreased with the increase of density at S1 sowing date,but increased with the increase of density at S2 sowing date.In addition,the peak viscosity,trough viscosity,final viscosity,and breakdown value generally increased with the increase of density under the two sowing dates.Parameters such as dough stability time and water absorption rate did not exhibit obvious regular pattern under different sowing dates and planting density,but all met the standards for strong gluten wheat.In summary,at sowing date S1,the planting density of Kexing 3302 at 315×10⁴—375×10⁴ plants/ha can achieve high quality and high yield.

To investigate the effects of long-term fertilization on yield formation and its physiological regulation mechanisms in double cropping late rice,it utilized a long-term fertilization experiment(initiated in 1981)in red paddy soils of Jinxian.Four typical treatments were selected:no fertilization(CK),single application of nitrogen-phosphorus-potassium(NPK),double dose of NPK(HNPK),and combined organic-inorganic fertilization(NPKM).Comparisons were made on double cropping late rice yield,dry matter accumulation,chlorophyll dynamics,and differential gene expression in leaves at fullheading and filling stages in the 42nd year of long-term fertilization.Results showed that long-term fertilization resulted in yields ranked as NPKM>HNPK>NPK>CK,with HNPK and NPKM treatments significantly surpassing NPK,showing increases of 29.63% and 57.18% respectively.Compared with NPK,both NPKM and HNPK significantly improved yield components:effective panicles,grains per panicle,and grain density increased by 16.98%—46.42%,8.68%—15.26%,3.69%—7.37%,respectively.Regarding dry matter accumulation,NPKM and HNPK significantly enhanced dry matter weight at all growth stages and promoted translocation of stem-leaf dry matter to panicles from filling to maturity.The contents of chlorophyll in NPKM and HNPK treatments were significantly higher than those in CK and NPK treatments at all stages,and NPKM delayed the decay of chlorophyll from filling stage to maturity stage.Correlation analysis revealed significant positive relationships between yield and dry matter accumulation from tillering to heading(△DM1)and filling to maturity(△DM3),while showed extremely negative correlation with chlorophyll reduction from grain filling to maturity(△S3).Transcriptome analysis demonstrated that long-term fertilization significantly affected gene expression in leaves during fullheading and filling stages,with differentially expressed genes primarily enriched in photosynthesis,carbon/nitrogen metabolism,signal transduction,and stress-related pathways.In conclusion,long-term fertilization regulates gene expression and combined organic-inorganic fertilization improved yield components,enhanced early-stage dry matter accumulation,promoted assimilate translocation from vegetative organs to panicles during grain filling,maintain higher chlorophyll levels,and delayed leaf senescence post-grain filling.This comprehensive mechanism achieves yield enhancement through strengthening source(enhancing photosynthetic capacity),expanding sink(increasing dry matter storage),and facilitating flow(promoting assimilate transport).

In order to explore the effect of straw interlayer on soil respiration and the chemical structural stability of organic carbon components during the remediation of saline-alkali soil,two experimental treatments were set up in the alfalfa-planting farmland at the Saline-Alkali Soil Improvement Experimental Demonstration Base in the Agricultural High-Tech Zone of Dongying City,Shandong Province:a straw interlayer treatment (S,with a 5 cm thick straw layer buried at a 35 cm depth) and a control (CK,without an interlayer). Soil respiration characteristics of the different treatments were analyzed,and comprehensive discussions were conducted in conjunction with soil pH,electrical conductivity(EC),organic carbon component content,and chemical structure characteristics of the soil profile.The results showed that:compared with CK,the S treatment significantly increased the soil respiration rate during the alfalfa growth period, with a maximum increase of 79.84%. Furthermore, the S treatment reduced soil EC in the straw interlayer (35—40 cm) and the overlying soil layer (0—35 cm), effectively inhibiting the upward migration of salt. The 40—50 cm soil layer was identified as a critical zone for organic carbon transformation. In this layer, the S treatment significantly increased SOC content (by 16.67%) and highly significantly elevated particulate organic carbon (POC) and dissolved organic carbon (DOC) contents (by 208.07% and 83.41%, respectively) compared with CK. Characterization of the molecular structure of organic carbon in the 40—50 cm layer revealed distinct responses. For DOC, the S treatment reduced the magnitude-weighted averages of unsaturation (by 30.60%) and aromaticity index (by 4.84%) compared with CK, decreasing the proportion of unstable carbon. For POC, the S treatment increased the relative abundances of alkyl C(10.32 percentage points)and O-alkyl C (8.39 percentage points) while reducing carboxyl C (14.24 percentage points), thereby enhancing POC structural stability. However, for bulk SOC, the S treatment decreased the proportions of alkyl C(3.14 percentage points) and aromatic C(3.38 percentage points) while increasing O-alkyl C(5.17 percentage points)and carboxyl C(1.56 percentage points). This shift indicated a decrease in recalcitrant carbon and an increase in labile carbon, resulting in reduced SOC structural stability. Correlation analysis showed that the significant increased in soil respiration was highly significantly and significantly positively correlated with POC and SOC contents in the critical soil layer, respectively. Specifically, the accumulation of O-alkyl C(a labile component) in the chemical structure of SOC reduced the stability of organic carbon,which was the main reason for the increase in soil respiration.In conclusion,incorporating a straw interlayer significantly increased soil respiration in the short term,which was closely related to the reduction in the stability of the organic carbon chemical structure in the key soil layer.Under future "carbon neutrality" strategies,research on the selection of interlayer materials should be considered.

Bacillus thuringiensis(Bt)produces multiple insecticidal proteins and serves as a vital biological control agent.This study aims to identify Bt strains with insecticidal activity against lepidopteran pests,thereby alleviating pest resistance pressure and expanding resource reserves.A total of 109 Bt strains were selected from soil of Hebei Province.The shape of parasporal crystals was observed under an oil microscope,and the insecticidal protein genotypes of the Bt strains were identified by PCR using 40 pairs of primers(including cry,cyt,and vip genotypes).The insecticidal activity bioassay was performed using five lepidopteran pests,including Plutella xylostella and Spodoptera litura.The molecular weight of crystal proteins was detected via SDS-PAGE.The shape of parasporal crystals from 90 strains was spherical,and the crystals from the remaining 19 strains were diamond-shaped.The detection rate of insecticidal protein genotypes reached 93.6%,with 29 distinct cry genotypes,1 cyt genotype,and 3 vip genotypes identified.A total of 91 strains possessed combinations of at least two insecticidal protein genotypes,among which 26 strains contained six or more,predominantly exhibiting cry+vip patterns.We found that 19 Bt strains showed high insecticidal activity against various lepidopteran pests such as P.xylostella. These strains primarily expressed proteins at 130,65 ku,encompassing lepidopteran-killing genotypes such as cry1,cry2,and cry15,consistent with PCR identification results.Here,we identified broad-spectrum insecticidal and highly toxic Bt strains against lepidopteran pests,and revealed its insecticidal genes.Our work provides an important candidate for the development of bioinsecticide.

In order to explore the structure and biological function of Ras related nuclear protein gene(RAN)in yak and resolve how it regulates the proliferation of yak cells and participates in protein synthesis,the CDS region sequence of RAN gene of Sangsang yak was cloned by RT-PCR using Sangsang yak kidney tissue cDNA as template,and bioinformatics analysis was carried out by a variety of software and online tools,the expression of the RAN gene in seven tissues of Sangsang yaks was detected by qPCR technology.The results showed that the CDS region of RAN gene in Sangsang yak was 651 bp in length,encoding 216 amino acids.Through homology comparison,it was found that the genetic relationship between Sangsang yak and wild yak and zebu was the closest,with a similarity of 99.2%,and the farthest from chicken,reaching 86.6%.The prediction results of RAN protein analysis showed that the molecular weight of the protein was 24.423 11 ku,the theoretical isoelectric point was 7.01,the total number of atoms was 3 449,and the molecular composition was C₁₁₀₉H₁₇₂₅N₂₉₅O₃₁₃S₇.RAN protein had no transmembrane structure and no potential sites for N-glycosylation,with 36 phosphorylation sites.The affinity and hydrophobicity were predicted and the instability coefficient was calculated,and it was found that the protein was a stable hydrophilic protein.According to the subcellular localization,the protein was found to be present in the Golgi apparatus,mitochondria,nucleus and cytoplasm in yak cells.Predictions of the RAN protein structure revealed that its higher-order structure consisted mainly of α-helices and did not contain β-turns.Protein interaction network results showed that there was an interaction between the RAN protein and RAN Binding Protein 1(RANBP1),RAN Binding Protein 2(RANBP2),RANGTPase activating protein 1(RANGAP1)and other proteins of Sangsang yak,and there was also an interaction between them.The expression level of the RAN gene in yak testicular tissue was significantly higher than in other tissues,while no expression was detected in muscle tissue.It successfully cloned the CDS region of the RAN gene and completed its bioinformatics analysis,and the expression of this gene in the tissue of Sangsang yak was also studied,and it was found that it played an important role in the development of the reproductive system,cell proliferation,disease prevention and control,and participation in protein synthesis.

The aim is to explore the biological function of the Lon gene in Glaesserella parasuis and its impact on the pathogenicity of the bacterium.A fusion gene fragment containing the homologous arms of the Lon gene and the kanamycin resistance gene selection marker was amplified using overlapping PCR,and a recombinant suicide plasmid pToPo-LR-Kana containing this gene fragment was constructed.The pToPo-LR-Kana was transformed into the parent strain ZJ1208 using natural transformation.The Lon gene-deleted strain ZJ1208-ΔLon was identified by kanamycin resistance screening,PCR,and sequencing.The differences between the wild-type strain ZJ1208 and the gene-deleted strain ZJ1208-ΔLon were compared through determination of growth rate,observation by transmission electron microscopy,stress resistance test,ultraviolet resistance test,serum resistance test,the biofilm formation assay,determination of capsule polysaccharide content and virulence test.The results showed that the Lon gene deletion strain ZJ1208-ΔLon was successfully obtained.The deletion strain had a significantly longer cell size,but its growth rate and number of outer membrane vesicles were similar to those of the wild-type strain ZJ1208.ZJ1208-ΔLon had significantly decreased tolerance to osmotic stress,oxidative stress,and heat stress,as well as significantly decreased resistance to ultraviolet radiation. Compared with the parent strain ZJ1208,the biofilm production capacity of ZJ1208-ΔLon and ZJ1208 was similar,but the capsular polysaccharide content of ZJ1208-ΔLon increased significantly,and the serum resistance and virulence in mice decreased significantly.The above results indicate that the deletion of Lon gene has an impact on multiple biological characteristics of G.parasuis,providing new information for further analysis of the biological function of Lon gene in G.parasuis.

OFP is a class of plant-specific transcription factors that play important roles in the regulation of plant organ morphogenesis and response to abiotic stresses.In order to study the characterization of soybean OFP transcription factor family members and their roles in drought stress and salt stress,bioinformatics methods were applied to identify and analyze soybean OFP family members.The results showed that:a total of 41 GmOFPs,named GmOFP-1—GmOFP-41,were identified in soybean;these genes were unevenly distributed on 19 chromosomes of soybean,encoding 152—414 amino acids;subcellular localization predicted that soybean OFP proteins were mainly localized in nucleus,chloroplasts,and mitochondria;a total of 10 conserved motifs were identified in soybean OFP proteins,conservative Motifs 1 and 2 were present in all OFP members.Phylogenetic analysis classified soybean and Arabidopsis OFP proteins into five subfamilies ClassⅠ—Class V,of which soybean OFP family genes were mainly distributed in ClassⅠ and Class Ⅲ.The collinearity analysis revealed that 75 pairs of genes in the soybean genome had collinearity,four pairs of genes had tandem duplications,and only two genes,GmOFP-2 and GmOFP-39,did not have collinearity,which indicated that gene fragment duplication was the main reason for the increase in the number of soybean OFP family members.The expression patterns of GmOFP gene family members under drought stress and salt stress treatments were analyzed by qRT-PCR,and the results showed that,compared with the control,16 members out of 41 GmOFP genes exhibited significant differences in gene expression levels after drought treatments,with significant up-regulation of the expression of GmOFP-15,GmOFP-17,and GmOFP-32,while the GmOFP-4,GmOFP-5,GmOFP-6,GmOFP-9,GmOFP-12,GmOFP-21,GmOFP-23,GmOFP-25,GmOFP-26,GmOFP-27,GmOFP-38,GmOFP-39,and GmOFP-40 were significantly down-regulated after drought treatment.Eight members of GmOFPs showed significant differences in gene expression levels after salt treatment,among which GmOFP-7,GmOFP-14,GmOFP-31,GmOFP-32,GmOFP-36,and GmOFP-40 were significantly up-regulated,and GmOFP-1 and GmOFP-15 were significantly down-regulated.The above results suggest that the soybean OFP gene family may have important functions in response to drought stress and salt stress.

To elucidate the molecular mechanisms underlying peanut pod responses to water stress,this study employed pot experiments combined with transcriptomic analysis.Using well-watered conditions as the control, we systematically investigated the effects of periodic drought and waterlogging stress during the flowering-pegging stage on yield,quality,and gene expression in peanut pods. Results demonstrated that both drought and waterlogging stresses significantly reduced peanut pod yield(by 26.43% and 77.69%,respectively)and crude fat content in kernels (by 9.46, 6.71 percentage points,respectively).Transcriptomic analysis further revealed 1 525 and 1 382 differentially expressed genes(DEGs)in the drought-stress and waterlogging-stress groups compared to the control, respectively, with down-regulated expression being predominant in both sets of DEGs. Specifically, drought stress suppressed six key metabolic processes related to lipid and fatty acid metabolism in peanut pods,with 88.38% of associated genes showing downregulated expression,indicating that lipid metabolic disruption may be the primary cause of yield and quality reduction under drought. Waterlogging stress predominantly interfered with pod metabolism and defense functions by downregulating genes associated with catalytic activity,transmembrane transport,redox reactions,and biosynthesis of secondary metabolites.Moreover, KEGG enrichment analysis indicated that metabolic pathways and biosynthesis of secondary metabolites were significantly affected under both water stress conditions. Key gene validation via qRT-PCR corroborated the RNA-seq data, confirming the reliability of the transcriptomic findings. In summary, this research elucidates the molecular basis of peanut pod response to water stress at the transcriptome level, demonstrating that lipid metabolic disruption is the primary factor underlying yield reduction and quality deterioration under drought stress, whereas peanut pods mitigate the adverse effects of waterlogging mainly by modulating the expression of genes associated with redox homeostasis and metabolic pathways.

To explore the disparities in overwintering rates and yields between Brassica napus L.and Brassica rapa L.in the cold and arid regions of the north,as well as to examine the correlation between diverse agronomic traits,yield,and cold resistance-enhancing traits,it utilized 45 B.napus L.and 22 B.rapa L.varieties as subjects.It conducted a statistical analysis of their overwintering rates,average yields and agronomic traits.It also studied seeding density experiments with B.napus L.and B.rapa L.varieties that exhibited similar yield levels,compared root traits between B.napus L.and B.rapa L..The results indicated that among the 67 varieties tested,the average overwintering rate of B.rapa L.(97.59%) was significantly higher than that of B.napus L.(65.87%).The average yield potential of B.napus L.was higher than that of B.rapa L..For B.rapa L.,which was capable of stable overwintering,increasing the seeding density significantly elevated the number of effective plants but did not augment the average yield.Conversely,for B.napus L.,its lower overwintering rate constrained the increase in the number of effective plants,thereby limiting the average yield.B.napus L.with a high overwintering rate exhibited agronomic traits such as higher branching positions and angular density,fewer secondary branches,total branches,and effective siliques per plant after overwintering.Comparison of root traits between B.napus L.and B.rapa L.showed that enlarged root systems,short hypocotyls,and growth points positioned below the ground surface were advantageous traits contributing to the robust cold resistance of B.rapa L..It proposes that breeding density-tolerance B.napus L.with root traits akin to those of B.rapa L.and with growth points situated below the ground surface represents a pivotal breeding direction for enhancing the overwintering rate of B.napus L.,fostering increased rapeseed yield,and ensuring oil supply stability.