Identification of a candidate QTG for seed number per silique by integrating QTL mapping and RNA-seq in Brassica napus L.

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.

Key genes and mechanisms underlying natural variation of silique length in oilseed rape(Brassica napus L.)germplasm

Silique length influences seed yield in oilseed rape.It shows extensive variation in germplasm resources,and identifying the underlying genes and regulatory mechanisms would advance breeding for the trait.In the present study,a genome-wide association study(GWAS)using 331 core accessions planted in 10 environments revealed 13 loci associated with silique length on chromosomes A01,A04,A07,A09,and C03,explaining 6.2%–19.2%of phenotypic variance.Physiological analysis showed that silique length variation was attributable to differences in silique growth rate and/or duration before four weeks after flowering,with levels of endogenous phytohormones(auxin,ethylene,and GA24,GA12,and GA44)playing an important role.Cytological analysis showed that silique length variation was due mainly to differences in cell number followed by cell size.Transcriptomic analysis of two pools of silique walls with opposite length extremes revealed 3248 differentially expressed genes(DEGs).These DEGs were enriched in several pathways(such as cell wall,cell division,and hormone metabolism)associated with cell proliferation and expansion and silique development.Integrating GWAS,RNA-seq,and functional annotation results revealed 15 candidate genes for the major associated locus q SL.A09-3.Of these,Bna A9.ARF18 and Bna A9.CYP78 A9 were validated by haplotype analysis followed by candidate gene association.Sequence variation in the coding region of Bna A9.ARF18 and expression of Bna A9.CYP78 A9 in silique walls were strongly associated with silique length.Our results provide an explanation for the natural variation of silique length in oilseed rape germplasm and offer useful information for its improvement.

Siliquent推出融合了TCP和RDMA的芯片产品

Siliquent Technologies公司推出一种能同时处理TCP卸载任务和RDMA操作的单芯片以太网处理器的样品。这种10Gbps先进以太网处理器是为以太网在承担LAN、集群互连和存储任务时进行复杂数据包转发工作而设计的。这种AEP芯片可通过PCI-X、SPI或PCIExpress接口与服务器系统接口。数据经过上层处理(ULP)发射器。

Interaction of brassinosteroid and cytokinin promotes ovule initiation and increases seed number per silique in Arabidopsis

Ovule initiation is a key step that strongly influences ovule number and seed yield.Notably,mutants with enhanced brassinosteroid(BR)and cytokinin(CK)signaling produce more ovules and have a higher seed number per silique(SNS)than wild-type plants.Here,we crossed BR-and CKrelated mutants to test whether these phytohormones function together in ovule initiation.We determined that simultaneously enhancing BR and CK contents led to higher ovule and seed numbers than enhancing BR or CK separately,and BR and CK enhanced each other.Further,the BR-response transcription factor BZR1 directly interacted with the CK-response transcription factor ARABIDOPSIS RESPONSE REGULATOR1(ARR1).Treatments with BR or BR plus CK strengthened this interaction and subsequent ARR1 targeting and induction of downstream genes to promote ovule initiation.Enhanced CK signaling partially rescued the reduced SNS phenotype of BR-deficient/insensitive mutants whereas enhanced BR signaling failed to rescue the low SNS of CK-deficient mutants,suggesting that BR regulates ovule initiation and SNS through CK-mediated and-independent pathways.Our study thus reveals that interaction between BR and CK promotes ovule initiation and increases seed number,providing important clues for increasing the seed yield of dicot crops.