水稻(Oryzasativa)分蘖数是水稻产量构成的关键.为了评价不同类型水稻种质资源的分蘖能力,筛选高分蘖的水稻种质,鉴定水稻分蘖性状相关调控基因,本研究利用两个亚群(Indica亚群和Noind亚群)的425份3K水稻核心种质作为研究材料,从分蘖起始至分蘖结束进行了 4次分蘖数调查(TN1～TN4),分析了两个亚群之间分蘖数的差异,利用全基因组关联分析(genome-wide association analysis,GWAS)定位与水稻分蘖数相关的数量性状位点(quantitative trait locus,QTL).结果表明,4次分蘖数调查的结果之间的变异系数差异不大,在36％～39％.Indica亚群的分蘖数显著高于Noind亚群的.全基因组关联分析定位到16个与水稻分蘖数显著关联的QTL,其中3个QTL与已知的影响分蘖数的基因共定位.结合基因注释、基因表达分析、SNP位点LD连锁不平衡分析和单倍型分析,从12个新QTL中鉴定出3个候选基因Os02g0503900、0s04g0614600和Os08g0138500,它们分别编码细胞色素P450蛋白、γ-氨基丁酸转氨酶蛋白和bHLH转录因子蛋白.对已知的影响分蘖数基因的单倍型和新候选基因的单倍型分别组合分析,筛选出5份高分蘖的优良种质,其优势单倍型组合的分蘖数显著高于劣势单倍型组合的.本研究从全基因组关联分析、SNP位点的LD连锁不平衡分析、基因表达差异分析、单倍型分析等多个方面筛选出3个新的水稻分蘖数候选基因,为进一步克隆水稻分蘖数相关基因,揭示水稻分蘖调控分子遗传机理,开展水稻分蘖数多基因组合分子设计育种奠定了基础.
Genome-wide Association Analysis of QTL for Tiller Number and Screening of Germplasm Resources in Rice(Oryza sativa)
The number of tillers is the key to rice(Oryza sativa)yield components.In order to evaluate the difference of tillering abili-ty of different types of rice germplasm resources,screen high-tillering rice germplasm,and identify the related regulatory genes of rice tillering traits,425 3K rice core germplasms from two subgroups(Indica subpopulation and Noind subpopulation)were used as research materials.Four tiller number surveys(TN1～TN4)were conducted from the beginning of tillering to the end of tillering.The difference of tiller number between these two subpopulations was analyzed.Genome-wide association analysis(GWAS)was used to map quantita-tive trait locus(QTL)associated with tiller number in rice.The results showed that there was no significant difference in the coefficient of variation among the four survey results of tiller number,ranging from 36％to 39％.The number of tillers in the Indica subpopulation is significantly higher than that in the Noind subpopulation.Genome-wide association analysis identified 16 QTL significantly associated with the number of tillers in rice,of which 3 QTL were co-mapped with known genes affecting tiller number,and 12 new QTL com-bined with gene annotation,gene expression analysis,LD linkage disequilibrium analysis at SNP site and haplotype analysis,identified three candidate genes:Os02g0503900,Os04g0614600 and Os08g0138500,encoding cytochrome P450 protein,γ-aminobutyric trans-aminase protein and bHLH transcription factor protein,respectively.The haplotypes of the known genes affecting the number of tillers and the haplotypes of the new candidate genes were analyzed separately,and 5 excellent germplasms with high tillers were screened out.Compared with the inferior haplotype combination.The tiller number of the advantageous haplotype combinations was significantly higher than that of the disadvantageous haplotype combinations.This study selected three new rice tiller number candidate genes,including genome association analysis,SNP site LD linkage unbalance analysis gene expression difference analysis,haplotype analysis and so on,lays the foundation for further cloning rice tiller related genes,revealing the molecular genetic mechanism of rice tiller regu-lation,and carrying out multi gene combination molecular design breeding for rice tiller number.
Oryza sativaTiller numberGenome-wide association analysisQuantitative trait locusGenetic improvement
NETL
NSTL
万方数据
