In order to study the mechanism of PSY1 gene in different ripe fruit colors of peppers, Y15016,Y15016-2,SP01,SP02 and Z1 were used as materials,and the functional properties of PSY protein and the expression of PSY1 gene in different fruit color materials of pepper were studied and analyzed by combining some bioinformatics methods.The results showed that the full-length PSY1 gene could be cloned in all five pepper varieties,and there was no difference in sequence.Gene structure analysis showed that the PSY1 gene contained six exons and five introns with a total length of 2 844 bp,and its CDS contained 1 260 bp and encoded 419 amino acids.Sequence alignment and phylogenetic tree analysis showed that the PSY protein of pepper was the closest to the homologous PSY protein of tomato and tobacco of the same family.The results of qRT-PCR analysis showed that the expression level of PSY1 gene in the five materials was lowest in the root tissue and highest in the leaf tissue.Besides,the PSY1 gene was expressed in all the tissues of these materials.The expression level of orange mutant Y15016-2 was higher than that of wild-type Y15016,while that of yellow mutant SP02 was significantly lower than that of wild-type SP01.At different stages of fruit development,the expression of PSY1 gene increased with the development of fruits,except for the decrease in stage Ⅲ,and reached the maximum value at the maturity stage(Ⅳ—Ⅴ)of different fruit color materials.The results of PSY1 gene promoter analysis showed that there was no difference in the sequences in the test materials.The results suggest that the differential expression of PSY1 gene may play an important role in the formation of peppers with different fruit colors.

Gibberellin pathway is an important pathway in plant flowering regulation.In order to understand the role of gibberellin pathway related genes in the regulation of radish flowering. The structure,physicochemical properties,chromosome distribution,promoter cis-elements and tissue-specific expression of gibberellin biosynthesis and signal transduction related genes in radish were analyzed by bioinformatics.The expression levels of these genes in radish varieties with different florescence were detected by Real-time fluorescence quantitative PCR(qPCR).The results showed there were 46 genes related to gibberellin biosynthesis and signal transduction in radish genome,among them,the gene numbers of CPS,KS,KO,KAO,GA20OX,GA3OX,GA2OX,GAI,RGA,RGL,GID1 and SKP2 were 2,1,2,2,9,5,12,1,1,4,3 and 4,respectively.They were unevenly distributed on 9 chromosomes,molecular weight of their coding proteins were 21.32—127.80 ku,and the isoelectric points of the proteins were from 4.72 to 9.04.The analysis of gene structure and conserved domain showed that the number of exons of these 46 genes ranged from 1 to 21,and some conserved motifs were shared by most genes.Promoter cis-elements analysis showed that the promoters of these 46 genes contained cis-elements related to light,gibberellin,auxin,ABA,SA,low temperature,drought,etc.Using radish gene expression database analysis,it was found that the expression levels of these 46 genes were different in different tissues and at different developmental stages;qPCR detection showed that there were significant differences in the expression of these genes between early flowering material Xinlimei and late flowering material wild radish,suggesting that they may be closely related to the reproductive growth of radish.

In order to explore the application effect of a new type of biochar-based compound fertilizer prepared by low temperature carbonization of waste organic sulfuric acid,a pot experiment was carried out with Xiaoding bacunshen as the test carrot variety and saline fluvo-aquic soil as the test soil. A total of 11 treatments were set up with 5 kinds of compound fertilizers and their carbon-based compound fertilizer formula treatments,and the effects of 5 kinds of biochar-based compound fertilizer formulas on carrot yield and soil nutrient content were studied. Results showed different fertilization significantly promoted the increase of fresh weight of carrot fleshy roots. Among them,carrots treated with 12-6-10 sulfur-based compound fertilizer with 15% carbon content had the highest fresh weight of fleshy root biomass,with a fresh weight of 313.85 g/plant,and the 10-5-20 chlorine-based fertilization treatment had the lowest yield of carrots. In contrast,10-5-20 chlorine based compound fertilizer had the lowest carrot yield. Compared with common compound fertilizers,those 5 kinds biochar-based compound fertilizers had significant effects on the increase of fresh weight of carrot fleshy root,with the range of increase of 2.1%-11.3%,and increased the accumulation of nitrogen,phosphorus and potassium in different degrees. In addition,the soil available N,P and K supply could be maintained by applying biochar-based compound fertilizer with 15% reduction of N,P and K nutrient application,and soil nutrients were still significantly increased in some periods. Application of biomass sulfonated carbon fertilizer could reduce the soil pH at the early stage of carrot growth,but there was no significant difference in soil pH at the mature stage of carrot. In conclusion,compared with common compound fertilizer,the application of biomass sulfonated carbon fertilizer could reduce the soil pH,increase the accumulation of nitrogen,phosphorus and potassium of carrot and the soil available nitrogen,olsen phosphorus and available potassium supply,which was conducive to carrot yield increase.

Carotenoids are the most widely distributed class of pigments in nature,which endow plants flowers,fruits and other organs with bright colors.The synthesis process of carotenoids contains a variety of metabolic enzyme genes.In order to reveal the molecular mechanism of carotenoid accumulation in yellow peeled zucchini,lay a foundation for further studying the function of carotenoid synthase gene in zucchini,this study identified zucchini carotenoid anabolism family genes based on the zucchini genome database,and further screened and cloned the key enzyme genes for carotenoid synthesis and metabolism by publicly published transcriptome data and qRT-PCR verification.The results showed that 48 carotenoid metabolizing enzyme gene members were detected in zucchini genome;and two key genes PSY1 and LCYE2 were screened out and showed different expression during the different developmental stages based on the transcriptome data of Sweet REBA/Lady Godiva.qRT-PCR analysis also showed that, except for PSY1 gene 0 d and LCYE2 gene 2 d, the relative expression of PSY1 and LCYE2 in different developmental stages of yellow peeled zucchini were significantly higher than that of white peeled zucchini.The full-length CDS of PSY1 and LCYE2 genes were cloned and sequencing analyzed from white and yellow peeled zucchini,respectively,which suggested that PSY1 genes of both materials were 51 bp more than the predicted coding sequence in zucchini reference genome,and were all consistent with the published sequence of PSY gene(GenBank number:XM_023695146.1),while the sequences of LCYE2 gene was not significantly different from the reference genome.Phylogenetic tree analysis showed that zucchini PSY1 was homologous to the reported Cucurbita moschata PSY(JN176311.1)with the best similarity as high as 98.80%.

The effect of different concentrations salt stress on seedling growth and expression of related genes were explored in this study. Firstly, salt tolerant variety Yura Hama Daikon and susceptible variety Wujinhong were selected according to germination under salt stress conditions among 11 cultivars.And then the seedling height(SH) and the leaf scorch index(LSI) of Yura Hama Daikon and Wujinhong were investigated under salt stress treatment.The results showed that SH decreased and LSI increased under salt stress in both varieties.Compared with the salt-sensitive variety Wujinhong,the salt-tolerant variety Yura Hama Daikon had a smaller decrease in SH and lower LSI.Under 200 mmol/L salt stress,SH and LSI of salt-tolerant Yura Hama Daikon were 46.18% and 20.56,respectively,while those of salt-sensitive Wujinhong were 75.25% and 56.11.The transcription of RsCAT and RsSOD genes was studied in salt-tolerant and susceptible varieties under different salt concentrations by qPCR.The expression of RsCAT gene was first increased and then decreased under low salt concentration treatment,and reached the maximum at 7 day.When treated with high salt concentration,the transcription of RsCAT in Wujinhong was the highest at 48 h,while the expression level in salt-tolerant varieties increased gradually and maintained for a longer time,reaching the highest at 7 day.After high salt concentration treatment,the transcription of RsSOD gene reached the highest expression level at 24 hours,and then maintained a higher level in salt-tolerant variety.In salt-sensitive varieties,the maximum expression level of RsSOD appeared at 14 day.The above results will lay foundation for revealing the mechanism of salt stress in radish and provide technical support for radish salt-tolerant breeding.

To explore the abortion characteristics and the genetic law of fertility restoring genes of NWB cytoplasm male sterile (CMS) in radish, 3 NWB CMS lines and 5 restoration materials were used as main test materials. The abortion characteristics of NWB CMS under different nuclear backgrounds were analyzed by paraffin section and scanning electron microscope, and the genetic law of restoring genes was revealed by analysis of fertility segregation of F₁, F₂, BC₁ population between sterile lines and restorer lines. The results showed that the different male sterile lines had different stamen morphology, but the pollen abortion of the CMS lines all started from the stage of mononuclear microspore, and there were differences in the degree of pollen degradation. A2 had shortening filament, shrinking anther with no visible pollen, the structure of A2's anther chamber was wrinkled and deformed, the shells of pollen grains were tightly packed together in a linear shape;A3 had normal filament, plump anther with no visible pollen, A3's anther chamber structure was basically normal, most of the pollen grains were degraded, and only a small amount were attached to the wall of the chamber;A4 had normal filament, plump anther with some nonfunctional pollen, there were a large number of unstained pollen grains in the anther chamber of A4, and the unstained pollen grains were sunken along three germ furrow to form polyhedron. The genetic laws of the 5 NWB CMS restorer materials were further analyzed, and the restorer genes were characterized by complete dominant inheritance. The number of the restorer genes varied with different materials, R1 contained 3 pairs of restorer genes, R2-R4 contained 2 pairs of restorer genes, and R5 contained 1 pair of restorer genes. In summary, NWB CMS stamen abortion morphology was different under different nuclear backgrounds, but the abortion period was the same, and the genetic rules of restoration genes vary from material to material. These results provide a certain theoretical basis for the breeding and utilization of radish NWB CMS.

FLC2 gene is a key gene affecting the bolting and flowering and plays an important role in the process of transition from vegetative growth to flower development in cruciferous plants. In order to breed a late-bolting green radish cultivar suitable for early spring cultivation, based on the function of FLC2 gene effecting the bolting, the late bolting radish variety Baiyuchun was used as the donor to transfer the late bolting character to Weifang radish by backcross breeding, and the polymorphism of FLC2 was studied during the process of backcross breeding to explore the effects of FLC2 in late bolting radish breeding. The results showed that the first intron of FLC2 gene had an insertion mutation with a length of about 1 628 bp in the late bolting donor, which was important for late bolting, and the homozygous insertion mutation had greater effect on late bolting than the heterozygous type did. It was found that the length of vernalization period affected the PCR amplification results on the first intron of FLC2. The short-term vernalization mainly affected the amplification of the first intron of the wild type FLC2, and the long-term vernalization mainly affected the amplification of intron in the insertion mutant, while the amplification of the two genotypes in the bolting and flowering period was not affected greatly. The amplification efficiency could be improved by improving the primers, but it could not eliminate the effect of vernalization on the first intron amplification of FLC2. The PCR result of normal plants at seedling stage was not as good as that at bolting stage. In conclusion, late bolting trait could be transfer into the acceptor radish by backcross continuously. When the heterozygous genotype was created by backcrossing, it could transfer the gene to its offsprings, and then the homozygous genotype could be obtained by self-crossing. The homozygous mutants with FLC2 insertion sequence could be confirmed by PCR detection at flowering stage, which could ensure the genetic stability and avoid the separation of late bolting traits in the offsprings.

To identify the pathogens causing bacterial soft rot on Chinese cabbage in Beijng,29 pathogenic strains were isolated and cultured from diseased samples,which were collected from several districts in Beijing. Morphology analyses,physiological and biochemical tests,molecular assay and pathogenicity test were performed to elucidate the causative bacterial pathogens. The results showed that the 17 strains were identified as Pectobacterium carotovorum subsp.brasiliensis (Pcb),and the remaining 12 strains were identified as P. carotovorum subsp. carotovorum (Pcc). Moreover,there were 9 atypical Pcc strains,which were unable to degrade citrate,or failed to grow at 37℃ and 7% NaCl,or weakly utilized palatinose,D-maltose and D-arabitol. The results of the pathogenicity analysis showed that all the strains expressed high pathogenicity with the exception of 2 Pcb strains and 1 Pcc strain exhibiting medium pathogenicity. The bacterial soft rot disease of Brassica rapa subsp. pekinensis occurred in Beijing and was caused mainly by Pcb and Pcc with high virulence,which will provide the basis for the disease control.

Harpins protein expressed by hypersensitive response and pathogenity gene(hrp) can induce the defense response of plant to diseases and insect pests of plant. By the way of agar solid plate, Erwinia carotovora pv. carotovora strain Ecc36 can produce high levels of extracellular enzymes. The Ecc36 strain could elicit the hypersensitive response(HR) in tobacco leaves. These results showed that some kind of hrp was in Ecc36 strain. Southern Blot analysis of Ecc36 with a hrpN gene probe labeled by DIG-dUTP showed that the Ecc36 strain possesses hrpN gene,named hrpN_EccPR. Through nucleotide sequence analysis,a 1 254 bp open reading frame(ORF) of Ecc36 hrpN was revealed. A Harpin protein(named HrpN_EccPR protein) encoded by hrpN_EccPR comprise 417 amino acid residues with 45.27 ku and pI 5.73 approximately. The deduced amino acid sequence of Ecc36 hrpN shares high homology with Harpin proteins of several other E. carotovora strains. The hrpN_EccPR gene was cloned into vector pET28a(+) for expression,and then transferred into the cells of E. coli strain BL21(DE3). The HrpN_EccPR protein was overexpressed in reconstructed BL21(DE3) when the strain was induced by IPTG. The purified HrpN_EccPR effectively elicits the HR in tobacco leaves. Those show HrpN_EccPR protein has the biological activity of stimulating the immune response of plants,and provide for further study on the mechanism of the defense response induced by HrpN_EccPR protein in plant.

In order to include the photosynthesis mechanism of summer maize in proper planting mode, in this paper, a split-plot experiment design was used to study the impact of planting densities(93 000, 81 000, 69 000, 57 000 plants/ha), row spacing modes(one plant per spot with equal row, three plants per spot with equal row and three plants per spot with wide and narrow row) and their interaction effects on net photosynthetic rate and its relative traits of a summer maize variety ZD958 at different growth stages(flowering stage, silking stage, earlier filling stage, later filling stage and full ripe stage).The results indicated that the row spacing mode of three plants per spot with wide and narrow row could significantly decrease net photosynthetic rate of ear leaves at flowering stage and full ripe stage.At the planting density of 81 000 plants/ha, the net photosynthetic rate was not associated with row spacing modes.Meanwhile, under the row spacing mode of one plant per spot with equal row, planting density did not significantly affect net photosynthetic rate of ear leaves.It was noteworthy that the carotenoid content was closely associated with planting densities, row spacing modes and their interaction effects.Under the row spacing mode of three plants per spot with equal row, the planting density of 93 000 plants/ha significantly decreased carotenoid content at the first three growth stages, while both the densities of 69 000 under the mode of three plants per spot with wide and narrow row and 57 000 plants/ha under the mode of one plant per spot with equal row could significantly reduce carotenoid content at the full ripe stage.It was also found that the maximum photochemical efficiency of PSⅡ was not influenced by planting densities, row spacing modes and their interaction effects.In general, the planting density of 81 000 plants/ha was not closely associated with row spacing modes, which was similar with the relationships between the row spacing mode of one plant per spot with equal row and planting densities.In these two circumstances, the net photosynthetic rate and its relative traits could maintain relatively higher levels.Our results could also supply experimental evidences for explaining the relationships among cropping patterns, photosynthetic products source and yield pool based on photosynthetic matters and water physiology(pigment content, fluorescence character, photosynthetic rate, and transpiration rate).

In order to increase improvement efficiency of radish cytoplasmic male sterile (Ogu CMS) restorers in Brassica napus L.,conventional techniques and improved techniques combined conventional techniques with microspore culture and marker-assisted selection (MAS) were studied.Results implied that there were great selection efficiency differences among different screening procedures in segregated populations.One of effective conventional improvement techniques was to cross hybrids with Ogu CMS lines,their progeny without Ogu CMS restorer genes would be sterile,which made selection be more visible at flowering stage and test crosses were not necessary.If modern biological techniques were utilized,the most effective screening procedures were cross,MAS and microspore culture.This procedure could decrease selection time from 8 generations to 3 generations,and experimental labor decreased by 90%.In this study,19 radish specific SCAR markers were screened,which could amplify unique and distinguishable bands in Ogu CMS restorers.However,only 10 radish specific SCAR markers could be screened in all Ogu CMS restorers.Results indicated that the radish specific markers of Ogu CMS restorer R581 were not the same as previous Ogu CMS restorers,the mean similarity ratio of R581 compared with other Ogu CMS restorers were from 48.28% to 93.10%.This study also found that radish specific markers could not distinguish restorers with high glucosinolates content from those with low glucosinolates content,which still need to be screened by analytical devices.In this study,6 Ogu CMS restorers were bred,which had low erucic acid content,low glucosinolates content,cold injury resistance,normal pod bearing rate and fine agronomic traits.These restorers made it feasible for Ogu CMS to be utilized in Brassica napus heterosis in China.