Verticillium longisporum(Vl43)is a soilborne hemibiotrophic fungal pathogen causing stem striping on oilseed rape(OSR)and severe yield losses.Breeding for resistant varieties is the most promising approach to control ...Verticillium longisporum(Vl43)is a soilborne hemibiotrophic fungal pathogen causing stem striping on oilseed rape(OSR)and severe yield losses.Breeding for resistant varieties is the most promising approach to control this disease.Here,we report the identification of Hva22c as a novel susceptibility factor and its potential for improving OSR resistance.Hva22c is a member of the Hva22 gene family,originally described for barley(Hordeum vulgare).Several Hva22 members have been located at the endoplasmic reticulum.Hva22c is up-regulated in response to Vl43 in both Arabidopsis and OSR.We demonstrate that knock-out of Hva22c in OSR by CRISPR/Cas9 and its homolog in Arabidopsis by T-DNA insertion reduced plants’susceptibility to Vl43 infection and impaired the development of disease symptoms.To understand the underlying mechanism,we analysed transcriptomic data from infected and non-infected roots of hva22c knock-out and wild type plants.We identified a homozygous mutant with frame-shifts in all four BnHva22c loci displaying a vastly altered transcriptional landscape at 6 dpi.Significantly,a large set of genes was suppressed under mock conditions including genes related to the endomembrane systems.Among the up-regulated genes we found several defense-related and phytohormone-responsive genes when comparing mutant to the wild type.These results demonstrate that Hva22c is functionally required for a fully compatible plant-fungus interaction.Its loss of function reduces plant susceptibility,most likely due to endoplasmatic reticulum and Golgi dysfunction accompanied by additionally activated defense responses.These findings can help improve OSR resistance to V.longisporum infection.展开更多
Genetic manipulation(either restraint or enhancement)of the biosynthesis pathway ofα-linolenic acid(ALA)in seed oil is an important goal in Brassica napus breeding.B.napus is a tetraploid plant whose genome often har...Genetic manipulation(either restraint or enhancement)of the biosynthesis pathway ofα-linolenic acid(ALA)in seed oil is an important goal in Brassica napus breeding.B.napus is a tetraploid plant whose genome often har-bors four and six homologous copies,respectively,of the two fatty acid desaturases FAD2 and FAD3,which con-trol the last two steps of ALA biosynthesis during seed oil accumulation.In this study,we compared their promoters,coding sequences,and expression levels in three high-ALA inbred lines 2006L,R8Q10,and YH25005,a low-ALA line A28,a low-ALA/high-oleic-acid accession SW,and the wildtype ZS11.The expression levels of most FAD2 and FAD3 homologs in the three high-ALA accessions were higher than those in ZS11 and much higher than those in A28 and SW.The three high-ALA accessions shared similar sequences with the pro-moters and CDSs of BnFAD3.C4 and BnFAD3.A3.In A28 and SW,substitution of three amino acid residues in BnFAD2.A5 and BnFAD2.C5,an absence of BnFAD2.C1 locus,and a 549 bp long deletion on the BnFAD3.A3 promoter were detected.The profile of BnFAD2 mutation in the two low-ALA accessions A28 and SW is different from that reported in previous studies.The mutations in BnFAD3 in the high-ALA accessions are reported for thefirst time.In identifying the sites of these mutations,we provide detailed information to aid the design of mole-cular markers for accelerated breeding schemes.展开更多
Plant height is a key plant architectural trait that affects the seed yield,harvest index and lodging resistance in Brassica napus L.,although the genetic mechanisms affecting plant height remain unclear.Here,a semi-d...Plant height is a key plant architectural trait that affects the seed yield,harvest index and lodging resistance in Brassica napus L.,although the genetic mechanisms affecting plant height remain unclear.Here,a semi-dwarf mutant,df34,was obtained by ethyl methanesulphonate-induced mutagenesis.Genetic analysis showed that the semi-dwarf phenotype is controlled by one semi-dominant gene,which was located on chromosome C03 using a bulked segregant analysis coupled with whole-genome sequencing,and this gene was named BnaSD.C3.Then BnaSD.C3 was fine-mapped to a 297.35-kb segment of the“Darmor-bzh”genome,but there was no potential candidate gene for the semi-dwarf trait underlying this interval.Furthermore,the interval was aligned to the Zhongshuang 11 reference genome.Finally,combining structural variation analysis,transcriptome sequencing,phytohormone analyses and gene annotation information,BnaC03G0466900ZS and BnaC03G0478900ZS were determined to be the most likely candidate genes affecting the plant height of df34.This study provides a novel major locus for breeding and new insights into the genetic architecture of plant height in B.napus.展开更多
α-Linolenic acid(ALA,18:3Δ9,12,15)is an essential fatty acid for humans since it is the precursor for the biosynthesis of omega-3 long-chain polyunsaturated fatty acids(LC-PUFA).Modern people generally suffer from d...α-Linolenic acid(ALA,18:3Δ9,12,15)is an essential fatty acid for humans since it is the precursor for the biosynthesis of omega-3 long-chain polyunsaturated fatty acids(LC-PUFA).Modern people generally suffer from deficiency of ALA because most staple food oils are low or lack ALA content.Biotechnological enrichment of ALA in staple oil crops is a promising strategy.Chia(Salvia hispanica)has the highest ALA content in its seed oil among known oil crops.In this study,the FAD2 and FAD3 genes from chia were engineered into a staple oil crop,oilseed rape(Brassica napus),via Agrobaterium tumefaciens-mediated transformation of their LP4-2A fusion gene construct driven by the seed-specific promoter P_(NapA).In seeds of T0,T1,and T2 lines,the average ALA contents were 20.86,23.54,and 24.92%,respectively,which were 2.21,2.68,and 3.03 folds of the non-transformed controls(9.42,8.78,and 8.22%),respectively.The highest seed ALA levels of T0,T1,and T2 plants were 38.41,35.98,and 39.19%respectively,which were 4.10-4.77 folds of the respective controls.FA-pathway enzyme genes(BnACCD,BnFATA,BnSAD,BnSCD,BnDGAT1,BnDGAT2,and BnDGAT3)and positive regulatory genes(BnWRI1,BnLEC1,BnL1L,BnLEC2,BnABI3,BnbZIP67,and BnMYB96)were all significantly up-regulated.In contrast,BnTT1,BnTT2,BnTT8,BnTT16,BnTTG1,and BnTTG2,encoding negative oil accumulation regulators but positive secondary metabolism regulators,were all significantly down-regulated.This means the foreign ShFAD2-ShFAD3 fusion gene,directly and indirectly,remodeled both positive and negative loci of the whole FA-related network in transgenic B.napus seeds.展开更多
Yellow seed trait is a desirable characteristic with potential for increasing seed quality and commercial value in rapeseed,and anthocyanin and proanthocyanidins(PAs)are major seed-coat pigments.Few transcription fact...Yellow seed trait is a desirable characteristic with potential for increasing seed quality and commercial value in rapeseed,and anthocyanin and proanthocyanidins(PAs)are major seed-coat pigments.Few transcription factors involved in the regulation of anthocyanin and PAs biosynthesis have been characterized in rapeseed.In this study,we identified a transcription factor gene BnbHLH92a(BnaA06T0441000ZS)in rapeseed.Overexpressing BnbHLH92a both in Arabidopsis and in rapeseed reduced levels of anthocyanin and PAs.Correspondingly,the expression profiles of anthocyanin and PA biosynthesis genes(TT3,BAN,TT8,TT18,and TTG1)were shown by quantitative real-time PCR to be inhibited in BnbHLH92a-overexpressing Arabidopsis seeds,indicating that BnbHLH92a represses the anthocyanin and PA biosynthesis pathway in Arabidopsis.BnbHLH92a physically interacts with the BnTTG1 protein and represses the biosynthesis of anthocyanins and PAs in rapeseed.BnbHLH92a also binds directly to the BnTT18 promoter and represses its expression.These results suggest that BnbHLH92a is a novel upstream regulator of flavonoid biosynthesis in B.napus.展开更多
Variation in patterns of recombination in plant genomes provides information about species evolution,genetic diversity and crop improvement. We investigated meiotic crossovers generated in biparental segregating and r...Variation in patterns of recombination in plant genomes provides information about species evolution,genetic diversity and crop improvement. We investigated meiotic crossovers generated in biparental segregating and reciprocal backcross populations of the allopolyploid genome of rapeseed(Brassica napus)(AACC, 2n = 38). A structured set of 1445 intercrossed lines was derived from two homozygous de novo genome-assembled parents that represented the major genetic clusters of semi-winter Chinese and winter European rapeseeds, and was used to increase QTL resolution and achieve genomic reciprocal introgression. A high-density genetic map constructed with 6161 genetic bins and anchored centromere regions was used to establish the pattern of recombination variation in each chromosome. Around 93%of the genome contained crossovers at a mean rate of 3.8 c M Mb^(-1), with the remaining 7% attributed to centromeres or low marker density. Recombination hotspots predominated in the A genome, including two-thirds of those associated with breeding introgression from B. rapa. Genetic background might affect recombination variation. Introgression of genetic diversity from European winter to Chinese semi-winter rapeseed showed an increase in crossover rate under the semi-winter environment. Evidence for an elevated recombination rate having historically contributed to selective trait improvement includes accumulation of favorable alleles for seed oil content on hotspots of chromosome A10. Conversely, strong artificial selection may affect recombination rate variation, as appears to be the case with a coldspot resulting from strong selection for glucosinolate alleles on A09. But the cold region would be promptly reactivated by crossing design indicated by the pedigree analysis. Knowledge of recombination hotspots and coldspots associated with QTL for 22 traits can guide selection strategies for introgression breeding between the two gene pools. These results and rich genomic resources broaden our understanding of recombination behavior in allopolyploids and may advance rapeseed genetic improvement.展开更多
Seed number per silique(SNPS)is one of seed yield components in rapeseed,but its genetic mechanism remains elusive.Here a double haploid(DH)population derived from a hybrid between female 6Q006with 35–40 SNPS and mal...Seed number per silique(SNPS)is one of seed yield components in rapeseed,but its genetic mechanism remains elusive.Here a double haploid(DH)population derived from a hybrid between female 6Q006with 35–40 SNPS and male 6W26 with 10–15 SNPS was investigated for SNPS in the year 2017,2018,2019 and 2021,and genotyped with Brassica 60K Illumina Infinium SNP array.An overlapping major QTL(qSNPS.C09)explaining 51.50%of phenotypic variance on average was narrowed to a 0.90 Mb region from 44.87 Mb to 45.77 Mb on chromosome C09 by BSA-seq.Subsequently,two DEGs in this interval were detected between extreme individuals in DH and F_2populations by transcriptome sequencing at7 and 14 days after pollination siliques.Of which,BnaC09g45400D encoded an adenine phosphoribosyltransferase 5(APT5)has a 48-bp InDel variation in the promoter of two parents.Candidate gene association analysis showed that this InDel variation was associated with SNPS in a nature population of rapeseed,where 54 accessions carrying the same haplotype as parent 6Q006 had higher SNPS than103 accessions carrying the same haplotype as parent 6W26.Collectively,the findings are helpful for rapeseed molecular breeding of SNPS,and provide new insight into the genetic and molecular mechanism of SNPS in rapeseed.展开更多
Seed weight is a component of seed yield in rapeseed(Brassica napus L.).Although quantitative trait loci(QTL)for seed weight have been reported in rapeseed,only a few causal quantitative trait genes(QTGs)have been ide...Seed weight is a component of seed yield in rapeseed(Brassica napus L.).Although quantitative trait loci(QTL)for seed weight have been reported in rapeseed,only a few causal quantitative trait genes(QTGs)have been identified,resulting in a limitation in understanding of seed weight regulation.We constructed a gene coexpression network at the early seed developmental stage using transcripts of 20,408 genes in QTL intervals and 1017 rapeseed homologs of known genes from other species.Among the 10 modules in this gene coexpression network,modules 1 and 2 were core modules and contained genes involved in source–flow–sink processes such as synthesis and transportation of fatty acid and protein,and photosynthesis.A hub gene SERINE CARBOXYPEPTIDASE-LIKE 19(SCPL19)was identified by candidate gene association analysis in rapeseed and functionally investigated using Arabidopsis T-DNA mutant and overexpression lines.Our study demonstrates the power of gene coexpression analysis to prioritize candidate genes from large candidate QTG sets and enhances the understanding of molecular mechanism for seed weight at the early developmental stage in rapeseed.展开更多
The leaf is the main organ for rapeseed photosynthesis,and its morphology influences photosynthetic efficiency and supports increased planting density and yield.However,the molecular regulatory mechanism of leaf morph...The leaf is the main organ for rapeseed photosynthesis,and its morphology influences photosynthetic efficiency and supports increased planting density and yield.However,the molecular regulatory mechanism of leaf morphology in Brassica napus is poorly understood,restricting progress in breeding for the trait.We describe a novel dominant mutation,curly leaf 1(cl1),which confers uneven dorsal–ventral axis development,irregular cellular structure and influenced gravitropic response in the seedling stage.The CL1 locus was mapped to a 1.573-Mb interval on chromosome A05 using simple sequence repeat(SSR)markers,and co-segregated with the phenotype of plants in the curly F2 population.A substitution(P62S)was identified in the highly conserved degron motif(GWSPV)of the IAA2 protein in the cl1mutant,and the P62S substitution impaired the interaction between IAA2 and TIR1 in the presence of auxin,influencing auxin signaling.The P62S substitution-induced curly leaf phenotype was verified by ectopic expression of Bna A05.iaa2 in Arabidopsis and B.napus.Our findings explain the function of IAA2 in rapeseed,providing a foundation for future investigation of auxin signaling and the mechanisms underlying leaf development in B.napus.展开更多
Glucosinolates(GSLs) and their hydrolytic products contribute to the quality traits of rapeseed flowering stalk tissues, such as taste, flavor and anticarcinogenic properties(Glucoraphanin). However, little is known a...Glucosinolates(GSLs) and their hydrolytic products contribute to the quality traits of rapeseed flowering stalk tissues, such as taste, flavor and anticarcinogenic properties(Glucoraphanin). However, little is known about the genetic mechanisms of GSL accumulation in rapeseed flowering stalks. In this study, the variation and genetic architecture of GSL metabolites in flowering stalk tissues were investigated for the first time among a panel of 107 accessions. All GSL compounds exhibited continuous and wide variations in the present population. Progoitrin,glucobrassicanapin and gluconapin were the most abundant GSL compounds. Five quantitative trait loci(QTL) significantly associated with three GSL compounds were identified by genome-wide association study. GRA_C04 was under selected during modern breeding, in which the ratio of lower GSL haplotype(HAP2) in the accessions bred before 1990(52.56%) was significantly lower than that after 1990(78.95%). Four candidate genes, BnaA01. SOT16, BnaA06. SOT17, Bna A06. MYB51a, and Bna A06. MYB51b, were identified in the GTL_A01 and 4OH_A06 regions.These findings provide new insights into GSL biosynthesis in flowering stalk tissues and facilitate quality improvement in rapeseed flowering stalks.展开更多
As global temperature rise,the threat of heat stress to rapeseed production is becoming more obvious.Exploring the response characteristics of two important biological pathways,oil accumulation and photosynthesis,to h...As global temperature rise,the threat of heat stress to rapeseed production is becoming more obvious.Exploring the response characteristics of two important biological pathways,oil accumulation and photosynthesis,to heat stress during B.napus seed filling is helpful in the genetic improvement of heat-tolerant rapeseed.The effects of heat stress on seed oil accumulation and chlorophyll fluorescence characteristics of 29 B.napus germplasms with different oil content and environmental sensitivity,including 6 rapeseed varieties which exhibited environmentsensitive/insensitive and with high,medium or low oil content,were tested by whole plant heat stress or the in vitro silique culture system.Both assay exhibited similar trend on oil content of the rapeseed germplasms.The heat effect on the chlorophyll fluorescence kinetic parameters F_(v)/F_(m),ETR and Y(Ⅱ)were also consistent.Heat stress significantly decreased oil content,although there was abundant genetic variation on heat tolerance among the genotypes.Correlation analysis showed that the decrease rate of F_(v)/F_(m) of silique heat-stressed B.napus developing seed was positive correlative to the decrease rate of mature seed oil content of the whole plant heat-stressed rapeseed(R=0.9214,P-value<0.01).Overall,the results indicated that heat stress inhibited oil accumulation and photosynthesis in B.napus developing seed.The decrease rate of chlorophyll fluorescence parameter F_(v)/F_(m) of heat-stressed developing seed could be used as the index of heat tolerant rapeseed identification.Further,two heat insensitive rapeseed varieties with high oil content were identified.展开更多
Reactive oxygen species(ROS)play a key role in a variety of biological processes,such as the perception of abiotic stress,the integration of different environmental signals,and the activation of stress response networ...Reactive oxygen species(ROS)play a key role in a variety of biological processes,such as the perception of abiotic stress,the integration of different environmental signals,and the activation of stress response networks.Salt stress could induce an increased ROS accumulation in plants,disrupting intracellular redox homeostasis,leading to posttranslational modifications(PTMs)of specific proteins,and eventually causing adaptive changes in metabolism.Here,we performed an iodoTMT-based proteomic approach to identify the sulfenylated proteins in B.napus root responsing to salt stress.Totally,1348 sulfenylated sites in 751 proteins were identified and these proteins were widely existed in different cell compartments and processes.Our study revealed that proteins with changed abundance and sulfenylation level in B.napus root under salt stress were mainly enriched in the biological processes of ion binding,glycolysis,ATP binding,and oxidative stress response.This study displays a landscape of sulfenylated proteins response to salt stress in B.napus root and provides some theoretical support for further understanding of the molecular mechanisms of redox regulation under salt stress in plants.展开更多
Brassica napus(B.napus)is a globally significant oilseed crop,making a substantial contribution to both human oil and livestock feed production.Enhancing seed weight is crucial for improving rapeseed yield;however,onl...Brassica napus(B.napus)is a globally significant oilseed crop,making a substantial contribution to both human oil and livestock feed production.Enhancing seed weight is crucial for improving rapeseed yield;however,only a limited number of seed weight-related genes have been functionally validated in B.napus thus far.UBIQUITINSPECIFIC PROTEASE 15(UBP15)belongs to the ubiquitin protease pathway and plays a maternal role in prolonging seed development in Arabidopsis.The potential utilization of UBP15 for enhancing seed yield in B.napus has remained unexplored until now.In this study,we identified the orthologs of UBP15 in B.napus and investigated its functionality using the CRISPR-Cas9 system.We generated mutant plants with multiple editing types targeting Bnaubp15s and successfully isolated T-DNA-free homozygous mutant lines that exhibited edits across four homologs of BnaUBP15 in T2 generation plants.Our preliminary data demonstrated that mutation of BnaUBP15s significantly reduced seed size,seed weight,and plant height while noticeably increasing the number of primary branches.These findings not only provide crucial evidence for further elucidating the molecular mechanism underlying the regulation of seed weight and size by BnaUBP15s but also offer promising novel germplasm for enhancing plant architecture.展开更多
Gibberellin 2-oxidases(GA2ox)are important enzymes that maintain the balance of bioactive GAs in plants.GA2ox genes have been identified and characterized in many plants,but these genes were not investigated in Brassi...Gibberellin 2-oxidases(GA2ox)are important enzymes that maintain the balance of bioactive GAs in plants.GA2ox genes have been identified and characterized in many plants,but these genes were not investigated in Brassica napus.Here,we identified 31 GA2ox genes in B.napus and 15 of these BnaGA2ox genes were distributed in the A and C subgenomes.Subcellular localization predictions suggested that all BnaGA2ox proteins were localized in the cytoplasm,and gene structure analysis showed that the BnaGA2ox genes contained 2–4 exons.Phylogenetic analysis indicated that BnGA2ox family proteins in monocotyledons and dicotyledons can be divided into four groups,including two C_(19)-GA2ox and two C_(20)-GA2ox clades.Group 4 is a C_(20)-GA2ox Class discovered recently.Most BnaGA2ox genes had a syntenic relationship with AtGA2ox genes.BnaGA2ox genes in the C subgenome had experienced stronger selection pressure than genes in the A subgenome.BnaGA2ox genes were highly expressed in specific tissues such as those involved in growth and development,and most of them were mainly involved in abiotic responses,regulation of phytohormones and growth and development.Our study provided a valuable evolutionary analysis of GA2ox genes in monocotyledons and dicotyledons,as well as an insight into the biological functions of GA2ox family genes in B.napus.展开更多
Nitrogen(N)is one of the basic nutrients and signals for plant development and deficiency of it would always limit the productions of crops in the field.Quantitative research on expression of N-stress responsive prote...Nitrogen(N)is one of the basic nutrients and signals for plant development and deficiency of it would always limit the productions of crops in the field.Quantitative research on expression of N-stress responsive proteins on a proteome level remains elusive.In order to gain a deep insight into the proteins responding to nitrogen stress in rapeseed(Brassica napus L.),comparative proteomic analysis was performed to investigate changes of protein expression profiles from the root,stem and leaf under different N concentrations,respectively.More than 200 differential abundance proteins(DAPs)were detected and categorized into groups according to annotations,including“binding and catalytic activity”,“involved in primary metabolism and cellular processes”,“stress-response”and so on.Variation in chlorophyll(Chl)content and antioxidant activities further revealed that oxidative stress raised with the increase of N concentration.Bioinformatics analysis based on the expression level of total proteins suggested these DAPs might play important roles in adaptation to N-stress conditions.Generally,these results provides a new aspect into N-stress responding proteins in Brassica plants.展开更多
Ascorbate peroxidase(APX)is a crucial H2O2 scavenger that utilizes ascorbic acid as an electron donor and plays a significant role in plant stress resistance.This study aims to identify and characterize the Brassica n...Ascorbate peroxidase(APX)is a crucial H2O2 scavenger that utilizes ascorbic acid as an electron donor and plays a significant role in plant stress resistance.This study aims to identify and characterize the Brassica napus L.APX gene family through genome and transcriptome sequencing,while also revealing their expression profile under low-temperature stress via transcriptome and proteome analysis.The results indicate the presence of 18 genes with three different conserved domains distributed in Brassica napus L.,which can be classified into three major branches based on phylogenetic analysis.Eleven members were predicted to have the low-temperature response component(LTR).Most APX genes exhibit up-regulated transcriptional expression under low temperature stress,particularly APX2,APX4,APX12,and APX18.In terms of proteomics data,only six members(APX2,APX4,APX8,APX12,APX17,and APX18)showed temporal specificity in their expression patterns.Therefore,this study provides valuable insights into the complexity of the APX family in the functional characterization of its genes for future research.展开更多
Oilseed rape(Brassica napus L.) is an allotetraploid(AACC,2n=38) crop,valued for its edible oil and protein content.seed yield and nutritional composition of rapeseed are influenced by its yield and oil quality traits...Oilseed rape(Brassica napus L.) is an allotetraploid(AACC,2n=38) crop,valued for its edible oil and protein content.seed yield and nutritional composition of rapeseed are influenced by its yield and oil quality traits.However,the genetic basis of yield-related and oil-quality traits remain ambiguous.A panel of 266 diversified oilseed rape accessions was genotyped using 223 simple sequence repeat(SSR) markers covering all 19 chromosomes to identify significant markers associated with yield and quality traits.Twelve yield-related and six quality traits were investigated in two consecutive years(2014 and 2015),with three replications in two environments(Changshun,CS;and Qinghe,QH).Using the model GLM with population structure and kinship(Q+K),a total of 25 significant SSR markers(P <0.001) were detected to be associated with these twelve yield-related and six quality traits,explaining 4.56%-19.17% of the phenotypic variation for each trait.Based on these markers,BnaA03g23490D, BnaC09g46370D,BnaA07g37150D,BnaA01g32590D, and BnaC09g37280D were identified as pleiotropic genes controlling multiple traits.These candidate genes illustrated the potential for the genetic understanding of yield and oil quality traits.Most importantly,these significant markers can be used for marker-assisted breeding of oilseed rape in different environments.展开更多
In 2020,diseased seedlings of winter oilseed rape(Brassica napus)with cankered taproots as well as abundant sclerotium-like structures in the soil surrounding the roots were found in Longxi County of Gansu province of...In 2020,diseased seedlings of winter oilseed rape(Brassica napus)with cankered taproots as well as abundant sclerotium-like structures in the soil surrounding the roots were found in Longxi County of Gansu province of northwestern China.A fungus with production of pycnidia was isolated from the diseased roots,and it was identified based on morphological characteristics,molecular phylogeny(ITS,LSU)and PCR detection with the specific primers.The fungus was identified as Leptosphaeria sclerotioides Gruyter,Aveskamp&Verkley[anamorph:Phoma sclerotioides(Preuss)ex Sacc.].Re-inoculation of isolates of P9 and P10 of L.sclerotioides on winter oilseed rape(B.napus cultivar‘Zhongshuang No.9’)in Wuhan caused formation of abundant sclerotium-like structures in soil surrounding the roots,but failed to produce root cankers as those observed in Gansu possibly due to lack of long peroid of low-temperature conditioning in Wuhan.In spite of this,plant height,pod number and seed yield of oilseed rape were significantly reduced in the treatment with L.sclerotioides P9 and P10,compared to the control treatment.To the best of our knowledge,this is the first report of L.sclerotioides on B.napus in China and the finding broadened our understanding about the natural distribution of this psychrophilic fungus.展开更多
基金supported by Bundesministerium für Bildung und Forschung(BMBF,Grant no.031B0033C)Bundesministerium für Ern?hrung und Landwirtschaft(BMEL,Grant no.22006516)Bundesanstalt für Landwirtschaft and Ern?hrung(BLE,Grant No.2814IP004)。
文摘Verticillium longisporum(Vl43)is a soilborne hemibiotrophic fungal pathogen causing stem striping on oilseed rape(OSR)and severe yield losses.Breeding for resistant varieties is the most promising approach to control this disease.Here,we report the identification of Hva22c as a novel susceptibility factor and its potential for improving OSR resistance.Hva22c is a member of the Hva22 gene family,originally described for barley(Hordeum vulgare).Several Hva22 members have been located at the endoplasmic reticulum.Hva22c is up-regulated in response to Vl43 in both Arabidopsis and OSR.We demonstrate that knock-out of Hva22c in OSR by CRISPR/Cas9 and its homolog in Arabidopsis by T-DNA insertion reduced plants’susceptibility to Vl43 infection and impaired the development of disease symptoms.To understand the underlying mechanism,we analysed transcriptomic data from infected and non-infected roots of hva22c knock-out and wild type plants.We identified a homozygous mutant with frame-shifts in all four BnHva22c loci displaying a vastly altered transcriptional landscape at 6 dpi.Significantly,a large set of genes was suppressed under mock conditions including genes related to the endomembrane systems.Among the up-regulated genes we found several defense-related and phytohormone-responsive genes when comparing mutant to the wild type.These results demonstrate that Hva22c is functionally required for a fully compatible plant-fungus interaction.Its loss of function reduces plant susceptibility,most likely due to endoplasmatic reticulum and Golgi dysfunction accompanied by additionally activated defense responses.These findings can help improve OSR resistance to V.longisporum infection.
基金The study was financially supported by Projects from Shaanxi Province(2021LLRH-07-03-01 and 2023-ZDLNY-07)Yangling Seed Industry Innovation(YLzy-yc2021-01).The funders had no role in study design,data collection and analysis,decision to publish,or preparation of the manuscript.
文摘Genetic manipulation(either restraint or enhancement)of the biosynthesis pathway ofα-linolenic acid(ALA)in seed oil is an important goal in Brassica napus breeding.B.napus is a tetraploid plant whose genome often har-bors four and six homologous copies,respectively,of the two fatty acid desaturases FAD2 and FAD3,which con-trol the last two steps of ALA biosynthesis during seed oil accumulation.In this study,we compared their promoters,coding sequences,and expression levels in three high-ALA inbred lines 2006L,R8Q10,and YH25005,a low-ALA line A28,a low-ALA/high-oleic-acid accession SW,and the wildtype ZS11.The expression levels of most FAD2 and FAD3 homologs in the three high-ALA accessions were higher than those in ZS11 and much higher than those in A28 and SW.The three high-ALA accessions shared similar sequences with the pro-moters and CDSs of BnFAD3.C4 and BnFAD3.A3.In A28 and SW,substitution of three amino acid residues in BnFAD2.A5 and BnFAD2.C5,an absence of BnFAD2.C1 locus,and a 549 bp long deletion on the BnFAD3.A3 promoter were detected.The profile of BnFAD2 mutation in the two low-ALA accessions A28 and SW is different from that reported in previous studies.The mutations in BnFAD3 in the high-ALA accessions are reported for thefirst time.In identifying the sites of these mutations,we provide detailed information to aid the design of mole-cular markers for accelerated breeding schemes.
基金the National Natural Science Foundation of China(32172065 and 32172095)the earmarked Fund for China Agriculture Research System(CARS-12)+1 种基金the Central Public-interest Scientific Institution Basal Research Fund,China(Y2022QC21)the Jiangsu Collaborative Innovation Center for Modern Crop Production,China。
文摘Plant height is a key plant architectural trait that affects the seed yield,harvest index and lodging resistance in Brassica napus L.,although the genetic mechanisms affecting plant height remain unclear.Here,a semi-dwarf mutant,df34,was obtained by ethyl methanesulphonate-induced mutagenesis.Genetic analysis showed that the semi-dwarf phenotype is controlled by one semi-dominant gene,which was located on chromosome C03 using a bulked segregant analysis coupled with whole-genome sequencing,and this gene was named BnaSD.C3.Then BnaSD.C3 was fine-mapped to a 297.35-kb segment of the“Darmor-bzh”genome,but there was no potential candidate gene for the semi-dwarf trait underlying this interval.Furthermore,the interval was aligned to the Zhongshuang 11 reference genome.Finally,combining structural variation analysis,transcriptome sequencing,phytohormone analyses and gene annotation information,BnaC03G0466900ZS and BnaC03G0478900ZS were determined to be the most likely candidate genes affecting the plant height of df34.This study provides a novel major locus for breeding and new insights into the genetic architecture of plant height in B.napus.
基金This work was supported by the National Natural Science Foundation of China(31871549,32001441 and 32272015)the Chongqing Research Program of Basic Research and Frontier Technology,China(cstc2015jcyjBX0143)+2 种基金the Fundamental Research Funds for the Central Universities,China(XDJK2020C038)the National Key R&D Program of China(2016YFD0100506)the Young Eagles Program of Chongqing Municipal Commission of Education,China(CY220219)。
文摘α-Linolenic acid(ALA,18:3Δ9,12,15)is an essential fatty acid for humans since it is the precursor for the biosynthesis of omega-3 long-chain polyunsaturated fatty acids(LC-PUFA).Modern people generally suffer from deficiency of ALA because most staple food oils are low or lack ALA content.Biotechnological enrichment of ALA in staple oil crops is a promising strategy.Chia(Salvia hispanica)has the highest ALA content in its seed oil among known oil crops.In this study,the FAD2 and FAD3 genes from chia were engineered into a staple oil crop,oilseed rape(Brassica napus),via Agrobaterium tumefaciens-mediated transformation of their LP4-2A fusion gene construct driven by the seed-specific promoter P_(NapA).In seeds of T0,T1,and T2 lines,the average ALA contents were 20.86,23.54,and 24.92%,respectively,which were 2.21,2.68,and 3.03 folds of the non-transformed controls(9.42,8.78,and 8.22%),respectively.The highest seed ALA levels of T0,T1,and T2 plants were 38.41,35.98,and 39.19%respectively,which were 4.10-4.77 folds of the respective controls.FA-pathway enzyme genes(BnACCD,BnFATA,BnSAD,BnSCD,BnDGAT1,BnDGAT2,and BnDGAT3)and positive regulatory genes(BnWRI1,BnLEC1,BnL1L,BnLEC2,BnABI3,BnbZIP67,and BnMYB96)were all significantly up-regulated.In contrast,BnTT1,BnTT2,BnTT8,BnTT16,BnTTG1,and BnTTG2,encoding negative oil accumulation regulators but positive secondary metabolism regulators,were all significantly down-regulated.This means the foreign ShFAD2-ShFAD3 fusion gene,directly and indirectly,remodeled both positive and negative loci of the whole FA-related network in transgenic B.napus seeds.
基金supported by the National Natural Science Foundation of China(32072093,31830067)the China Agriculture Research System of MOF and MARA,the Science and Enterprise Consortium Project of Chongqing(cqnyncw-kqlhtxm)+1 种基金the Innovation and Entrepreneurship Training Program for Undergraduates(S202010635197)the 111 Project(B12006).
文摘Yellow seed trait is a desirable characteristic with potential for increasing seed quality and commercial value in rapeseed,and anthocyanin and proanthocyanidins(PAs)are major seed-coat pigments.Few transcription factors involved in the regulation of anthocyanin and PAs biosynthesis have been characterized in rapeseed.In this study,we identified a transcription factor gene BnbHLH92a(BnaA06T0441000ZS)in rapeseed.Overexpressing BnbHLH92a both in Arabidopsis and in rapeseed reduced levels of anthocyanin and PAs.Correspondingly,the expression profiles of anthocyanin and PA biosynthesis genes(TT3,BAN,TT8,TT18,and TTG1)were shown by quantitative real-time PCR to be inhibited in BnbHLH92a-overexpressing Arabidopsis seeds,indicating that BnbHLH92a represses the anthocyanin and PA biosynthesis pathway in Arabidopsis.BnbHLH92a physically interacts with the BnTTG1 protein and represses the biosynthesis of anthocyanins and PAs in rapeseed.BnbHLH92a also binds directly to the BnTT18 promoter and represses its expression.These results suggest that BnbHLH92a is a novel upstream regulator of flavonoid biosynthesis in B.napus.
基金supported by the National Key Research and Development Program of China (2021YFF1000100)the National Natural Science Foundation of China (31970564 and 32171982)the National Key Research and Development Program of China (2016YFD0100305)。
文摘Variation in patterns of recombination in plant genomes provides information about species evolution,genetic diversity and crop improvement. We investigated meiotic crossovers generated in biparental segregating and reciprocal backcross populations of the allopolyploid genome of rapeseed(Brassica napus)(AACC, 2n = 38). A structured set of 1445 intercrossed lines was derived from two homozygous de novo genome-assembled parents that represented the major genetic clusters of semi-winter Chinese and winter European rapeseeds, and was used to increase QTL resolution and achieve genomic reciprocal introgression. A high-density genetic map constructed with 6161 genetic bins and anchored centromere regions was used to establish the pattern of recombination variation in each chromosome. Around 93%of the genome contained crossovers at a mean rate of 3.8 c M Mb^(-1), with the remaining 7% attributed to centromeres or low marker density. Recombination hotspots predominated in the A genome, including two-thirds of those associated with breeding introgression from B. rapa. Genetic background might affect recombination variation. Introgression of genetic diversity from European winter to Chinese semi-winter rapeseed showed an increase in crossover rate under the semi-winter environment. Evidence for an elevated recombination rate having historically contributed to selective trait improvement includes accumulation of favorable alleles for seed oil content on hotspots of chromosome A10. Conversely, strong artificial selection may affect recombination rate variation, as appears to be the case with a coldspot resulting from strong selection for glucosinolate alleles on A09. But the cold region would be promptly reactivated by crossing design indicated by the pedigree analysis. Knowledge of recombination hotspots and coldspots associated with QTL for 22 traits can guide selection strategies for introgression breeding between the two gene pools. These results and rich genomic resources broaden our understanding of recombination behavior in allopolyploids and may advance rapeseed genetic improvement.
基金supported by the National Basic Research Program of China(2015CB150201)the Natural Science Foundation of Chongqing(cstc2019jcyj-bshX0055,cstc2019jcyj-zdxmX0012cstc2020jcyj-msxmX0461)。
文摘Seed number per silique(SNPS)is one of seed yield components in rapeseed,but its genetic mechanism remains elusive.Here a double haploid(DH)population derived from a hybrid between female 6Q006with 35–40 SNPS and male 6W26 with 10–15 SNPS was investigated for SNPS in the year 2017,2018,2019 and 2021,and genotyped with Brassica 60K Illumina Infinium SNP array.An overlapping major QTL(qSNPS.C09)explaining 51.50%of phenotypic variance on average was narrowed to a 0.90 Mb region from 44.87 Mb to 45.77 Mb on chromosome C09 by BSA-seq.Subsequently,two DEGs in this interval were detected between extreme individuals in DH and F_2populations by transcriptome sequencing at7 and 14 days after pollination siliques.Of which,BnaC09g45400D encoded an adenine phosphoribosyltransferase 5(APT5)has a 48-bp InDel variation in the promoter of two parents.Candidate gene association analysis showed that this InDel variation was associated with SNPS in a nature population of rapeseed,where 54 accessions carrying the same haplotype as parent 6Q006 had higher SNPS than103 accessions carrying the same haplotype as parent 6W26.Collectively,the findings are helpful for rapeseed molecular breeding of SNPS,and provide new insight into the genetic and molecular mechanism of SNPS in rapeseed.
基金provided by the National Natural Science Foundation of China(32201776)the Natural Science Foundation of Chongqing(cstc2019jcyj-bsh X0055,cstc2019jcyj-zdxm X0012)。
文摘Seed weight is a component of seed yield in rapeseed(Brassica napus L.).Although quantitative trait loci(QTL)for seed weight have been reported in rapeseed,only a few causal quantitative trait genes(QTGs)have been identified,resulting in a limitation in understanding of seed weight regulation.We constructed a gene coexpression network at the early seed developmental stage using transcripts of 20,408 genes in QTL intervals and 1017 rapeseed homologs of known genes from other species.Among the 10 modules in this gene coexpression network,modules 1 and 2 were core modules and contained genes involved in source–flow–sink processes such as synthesis and transportation of fatty acid and protein,and photosynthesis.A hub gene SERINE CARBOXYPEPTIDASE-LIKE 19(SCPL19)was identified by candidate gene association analysis in rapeseed and functionally investigated using Arabidopsis T-DNA mutant and overexpression lines.Our study demonstrates the power of gene coexpression analysis to prioritize candidate genes from large candidate QTG sets and enhances the understanding of molecular mechanism for seed weight at the early developmental stage in rapeseed.
基金supported by the National Natural Science Foundation of China(31971902,32001509)China Agriculture Research System of MOF and MARA。
文摘The leaf is the main organ for rapeseed photosynthesis,and its morphology influences photosynthetic efficiency and supports increased planting density and yield.However,the molecular regulatory mechanism of leaf morphology in Brassica napus is poorly understood,restricting progress in breeding for the trait.We describe a novel dominant mutation,curly leaf 1(cl1),which confers uneven dorsal–ventral axis development,irregular cellular structure and influenced gravitropic response in the seedling stage.The CL1 locus was mapped to a 1.573-Mb interval on chromosome A05 using simple sequence repeat(SSR)markers,and co-segregated with the phenotype of plants in the curly F2 population.A substitution(P62S)was identified in the highly conserved degron motif(GWSPV)of the IAA2 protein in the cl1mutant,and the P62S substitution impaired the interaction between IAA2 and TIR1 in the presence of auxin,influencing auxin signaling.The P62S substitution-induced curly leaf phenotype was verified by ectopic expression of Bna A05.iaa2 in Arabidopsis and B.napus.Our findings explain the function of IAA2 in rapeseed,providing a foundation for future investigation of auxin signaling and the mechanisms underlying leaf development in B.napus.
基金supported by the Key Research and Development project of Hubei Province (Grant Nos. 2020BBB083, 2021BBA097 and 2021BBA102)the National Key Research and Development Program of China (Grant No. 2016YFD0100202)。
文摘Glucosinolates(GSLs) and their hydrolytic products contribute to the quality traits of rapeseed flowering stalk tissues, such as taste, flavor and anticarcinogenic properties(Glucoraphanin). However, little is known about the genetic mechanisms of GSL accumulation in rapeseed flowering stalks. In this study, the variation and genetic architecture of GSL metabolites in flowering stalk tissues were investigated for the first time among a panel of 107 accessions. All GSL compounds exhibited continuous and wide variations in the present population. Progoitrin,glucobrassicanapin and gluconapin were the most abundant GSL compounds. Five quantitative trait loci(QTL) significantly associated with three GSL compounds were identified by genome-wide association study. GRA_C04 was under selected during modern breeding, in which the ratio of lower GSL haplotype(HAP2) in the accessions bred before 1990(52.56%) was significantly lower than that after 1990(78.95%). Four candidate genes, BnaA01. SOT16, BnaA06. SOT17, Bna A06. MYB51a, and Bna A06. MYB51b, were identified in the GTL_A01 and 4OH_A06 regions.These findings provide new insights into GSL biosynthesis in flowering stalk tissues and facilitate quality improvement in rapeseed flowering stalks.
基金funded by the Natural Science Foundation of Zhejiang Province(LY20C130006)the National Natural Science Foundation of China(32172018)the State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products(2010DS700124-ZZ1805).
文摘As global temperature rise,the threat of heat stress to rapeseed production is becoming more obvious.Exploring the response characteristics of two important biological pathways,oil accumulation and photosynthesis,to heat stress during B.napus seed filling is helpful in the genetic improvement of heat-tolerant rapeseed.The effects of heat stress on seed oil accumulation and chlorophyll fluorescence characteristics of 29 B.napus germplasms with different oil content and environmental sensitivity,including 6 rapeseed varieties which exhibited environmentsensitive/insensitive and with high,medium or low oil content,were tested by whole plant heat stress or the in vitro silique culture system.Both assay exhibited similar trend on oil content of the rapeseed germplasms.The heat effect on the chlorophyll fluorescence kinetic parameters F_(v)/F_(m),ETR and Y(Ⅱ)were also consistent.Heat stress significantly decreased oil content,although there was abundant genetic variation on heat tolerance among the genotypes.Correlation analysis showed that the decrease rate of F_(v)/F_(m) of silique heat-stressed B.napus developing seed was positive correlative to the decrease rate of mature seed oil content of the whole plant heat-stressed rapeseed(R=0.9214,P-value<0.01).Overall,the results indicated that heat stress inhibited oil accumulation and photosynthesis in B.napus developing seed.The decrease rate of chlorophyll fluorescence parameter F_(v)/F_(m) of heat-stressed developing seed could be used as the index of heat tolerant rapeseed identification.Further,two heat insensitive rapeseed varieties with high oil content were identified.
基金funded by the Major Scientific and Technological Projects of Xinjiang Production and Construction Corps of China[2018AA005]and the 111 Project[B20051]supported by the PTM Biolabs lnc.[Hangzhou,China]for technical assistance.
文摘Reactive oxygen species(ROS)play a key role in a variety of biological processes,such as the perception of abiotic stress,the integration of different environmental signals,and the activation of stress response networks.Salt stress could induce an increased ROS accumulation in plants,disrupting intracellular redox homeostasis,leading to posttranslational modifications(PTMs)of specific proteins,and eventually causing adaptive changes in metabolism.Here,we performed an iodoTMT-based proteomic approach to identify the sulfenylated proteins in B.napus root responsing to salt stress.Totally,1348 sulfenylated sites in 751 proteins were identified and these proteins were widely existed in different cell compartments and processes.Our study revealed that proteins with changed abundance and sulfenylation level in B.napus root under salt stress were mainly enriched in the biological processes of ion binding,glycolysis,ATP binding,and oxidative stress response.This study displays a landscape of sulfenylated proteins response to salt stress in B.napus root and provides some theoretical support for further understanding of the molecular mechanisms of redox regulation under salt stress in plants.
基金This work was supported by the National Key Research and Development Program of China(2022YFD1200400)National Natural Science Foundation of China(32072099,31971977).
文摘Brassica napus(B.napus)is a globally significant oilseed crop,making a substantial contribution to both human oil and livestock feed production.Enhancing seed weight is crucial for improving rapeseed yield;however,only a limited number of seed weight-related genes have been functionally validated in B.napus thus far.UBIQUITINSPECIFIC PROTEASE 15(UBP15)belongs to the ubiquitin protease pathway and plays a maternal role in prolonging seed development in Arabidopsis.The potential utilization of UBP15 for enhancing seed yield in B.napus has remained unexplored until now.In this study,we identified the orthologs of UBP15 in B.napus and investigated its functionality using the CRISPR-Cas9 system.We generated mutant plants with multiple editing types targeting Bnaubp15s and successfully isolated T-DNA-free homozygous mutant lines that exhibited edits across four homologs of BnaUBP15 in T2 generation plants.Our preliminary data demonstrated that mutation of BnaUBP15s significantly reduced seed size,seed weight,and plant height while noticeably increasing the number of primary branches.These findings not only provide crucial evidence for further elucidating the molecular mechanism underlying the regulation of seed weight and size by BnaUBP15s but also offer promising novel germplasm for enhancing plant architecture.
基金supported by the Chongqing Academy of Agricultural Sciences Youth Innovation Team Project(NKY-2018QC01)Chongqing Finance Special Project(NKY-2022AC002)+2 种基金the Natural Science Foundation Project of Yongchuan(2021yc-jckx20013)the Technology Innovation and Application Development(Surface)Project of Yongchuan(2021yc-cxfz30007)the National Oilseed Rape Industrial Technology System Sanxia Comprehensive Experiment Station Project(CARS-13).
文摘Gibberellin 2-oxidases(GA2ox)are important enzymes that maintain the balance of bioactive GAs in plants.GA2ox genes have been identified and characterized in many plants,but these genes were not investigated in Brassica napus.Here,we identified 31 GA2ox genes in B.napus and 15 of these BnaGA2ox genes were distributed in the A and C subgenomes.Subcellular localization predictions suggested that all BnaGA2ox proteins were localized in the cytoplasm,and gene structure analysis showed that the BnaGA2ox genes contained 2–4 exons.Phylogenetic analysis indicated that BnGA2ox family proteins in monocotyledons and dicotyledons can be divided into four groups,including two C_(19)-GA2ox and two C_(20)-GA2ox clades.Group 4 is a C_(20)-GA2ox Class discovered recently.Most BnaGA2ox genes had a syntenic relationship with AtGA2ox genes.BnaGA2ox genes in the C subgenome had experienced stronger selection pressure than genes in the A subgenome.BnaGA2ox genes were highly expressed in specific tissues such as those involved in growth and development,and most of them were mainly involved in abiotic responses,regulation of phytohormones and growth and development.Our study provided a valuable evolutionary analysis of GA2ox genes in monocotyledons and dicotyledons,as well as an insight into the biological functions of GA2ox family genes in B.napus.
基金funded by Modern Agro-Industry Technology Research System of China(CARS-12)Independent Innovation Project of SAAS(2022ZZCX004)+5 种基金1+9 Open Competition Project of SAAS(1+9KJGG002,1+9KJGG001)the Accurate Identification Project of Crop Germplasm from Sichuan Provincial Finance DepartmentSichuan Science and Technology Program(2022ZDZX0015)Sichuan Crop Breeding Community(2021YFYZ0018)Disciplinary Construction Project for Modern Agriculture in SAAS(2021XKJS003)Chengdu Science and Technology Project(2021-YF09-00062-SN).
文摘Nitrogen(N)is one of the basic nutrients and signals for plant development and deficiency of it would always limit the productions of crops in the field.Quantitative research on expression of N-stress responsive proteins on a proteome level remains elusive.In order to gain a deep insight into the proteins responding to nitrogen stress in rapeseed(Brassica napus L.),comparative proteomic analysis was performed to investigate changes of protein expression profiles from the root,stem and leaf under different N concentrations,respectively.More than 200 differential abundance proteins(DAPs)were detected and categorized into groups according to annotations,including“binding and catalytic activity”,“involved in primary metabolism and cellular processes”,“stress-response”and so on.Variation in chlorophyll(Chl)content and antioxidant activities further revealed that oxidative stress raised with the increase of N concentration.Bioinformatics analysis based on the expression level of total proteins suggested these DAPs might play important roles in adaptation to N-stress conditions.Generally,these results provides a new aspect into N-stress responding proteins in Brassica plants.
基金supported by the Fundamental Research Project of Shanxi Province(202203021211276)Major Program of Shanxi Province(202201140601025-5)The Science and Technology Innovated Project of Shanxi Agricultural University(CXGC2023050).
文摘Ascorbate peroxidase(APX)is a crucial H2O2 scavenger that utilizes ascorbic acid as an electron donor and plays a significant role in plant stress resistance.This study aims to identify and characterize the Brassica napus L.APX gene family through genome and transcriptome sequencing,while also revealing their expression profile under low-temperature stress via transcriptome and proteome analysis.The results indicate the presence of 18 genes with three different conserved domains distributed in Brassica napus L.,which can be classified into three major branches based on phylogenetic analysis.Eleven members were predicted to have the low-temperature response component(LTR).Most APX genes exhibit up-regulated transcriptional expression under low temperature stress,particularly APX2,APX4,APX12,and APX18.In terms of proteomics data,only six members(APX2,APX4,APX8,APX12,APX17,and APX18)showed temporal specificity in their expression patterns.Therefore,this study provides valuable insights into the complexity of the APX family in the functional characterization of its genes for future research.
基金supported by National Natural Science Foundation of China(No.32070217)Subsidy project from NSFC of Guizhou Academy of Agricultural Sciences(No.[2021]50)+2 种基金The Scientific and Technological Key Program of Guizhou province(No.Qiankehezhicheng[2022]Key 031,025and 026)The Agricultural Scientific and Technological Research Projects of Guizhou province(No.Qiankehezhicheng[2020]1Y109 and 1Y106Youth Foundation of Guizhou Academy of Agricultural Sciences(No.[2021]07).
文摘Oilseed rape(Brassica napus L.) is an allotetraploid(AACC,2n=38) crop,valued for its edible oil and protein content.seed yield and nutritional composition of rapeseed are influenced by its yield and oil quality traits.However,the genetic basis of yield-related and oil-quality traits remain ambiguous.A panel of 266 diversified oilseed rape accessions was genotyped using 223 simple sequence repeat(SSR) markers covering all 19 chromosomes to identify significant markers associated with yield and quality traits.Twelve yield-related and six quality traits were investigated in two consecutive years(2014 and 2015),with three replications in two environments(Changshun,CS;and Qinghe,QH).Using the model GLM with population structure and kinship(Q+K),a total of 25 significant SSR markers(P <0.001) were detected to be associated with these twelve yield-related and six quality traits,explaining 4.56%-19.17% of the phenotypic variation for each trait.Based on these markers,BnaA03g23490D, BnaC09g46370D,BnaA07g37150D,BnaA01g32590D, and BnaC09g37280D were identified as pleiotropic genes controlling multiple traits.These candidate genes illustrated the potential for the genetic understanding of yield and oil quality traits.Most importantly,these significant markers can be used for marker-assisted breeding of oilseed rape in different environments.
基金supported by the Earmarked Fund for CARS-12 from National Modern Agricultural Technology System.
文摘In 2020,diseased seedlings of winter oilseed rape(Brassica napus)with cankered taproots as well as abundant sclerotium-like structures in the soil surrounding the roots were found in Longxi County of Gansu province of northwestern China.A fungus with production of pycnidia was isolated from the diseased roots,and it was identified based on morphological characteristics,molecular phylogeny(ITS,LSU)and PCR detection with the specific primers.The fungus was identified as Leptosphaeria sclerotioides Gruyter,Aveskamp&Verkley[anamorph:Phoma sclerotioides(Preuss)ex Sacc.].Re-inoculation of isolates of P9 and P10 of L.sclerotioides on winter oilseed rape(B.napus cultivar‘Zhongshuang No.9’)in Wuhan caused formation of abundant sclerotium-like structures in soil surrounding the roots,but failed to produce root cankers as those observed in Gansu possibly due to lack of long peroid of low-temperature conditioning in Wuhan.In spite of this,plant height,pod number and seed yield of oilseed rape were significantly reduced in the treatment with L.sclerotioides P9 and P10,compared to the control treatment.To the best of our knowledge,this is the first report of L.sclerotioides on B.napus in China and the finding broadened our understanding about the natural distribution of this psychrophilic fungus.
