研究盐胁迫、干旱胁迫下甘蓝型油菜的发芽率,寻找与发芽率相关联的分子标记,可为油菜逆境胁迫下种子萌发的分子标记辅助育种提供理论依据.本研究以甘蓝型黄籽油菜GH06和甘蓝型黑籽油菜P174为亲本,通过单粒传法(single seed descent,SSD)连续自交9代构建重组自交系群体.采用16 g L-1NaCl溶液进行盐胁迫,20％的PEG-6000溶液模拟干旱胁迫,处理重组自交系种子并统计其发芽率.实验室构建的SNP遗传图谱,包含2795个SNP多态性标记位点,总长1832.9 cM,相邻标记间平均距离为0.66 cM.利用该图谱并采用复合区间作图法(CIM)分析2种胁迫条件下第3天、第4天及累计4d后发芽率的QTL.共检测到19个QTL,分布于A01、A03、A06、A07、A09和C06染色体上.其中,11个盐胁迫相关的QTL可解释的变异为4.9％～10.9％,8个干旱胁迫相关的QTL可解释的变异为3.8％～6.9％;并且在A03和A09染色体上,盐胁迫和干旱胁迫下检测到的QTL有相近区段.研究结果表明油菜种子发芽率属于典型的数量性状,受环境影响较大;且随着胁迫时间的延长,油菜种子启动了不同的基因来响应环境胁迫.
QTL Mapping for Germination Percentage under Salinity and Drought Stresses in Brassica napus L.Using a SNP Genetic Map
The objective of this study was to identify QTLs for seed germination percentage under salinity and drought stresses in Brassica napus L.using a recombinant inbred line (RIL) population derived from the cross between yellow-seeded GH06 (female parent) and black-seeded P174 (male parent).The RILs were F11 developed via single-seed-descent propagation.QTLs for germination percentage under 16 g L-1 NaC1 and 20％ PEG-6000 (w/w) treatment,after four-day treatment and on the third and fourth day,were detected using the composite interval mapping (CIM) method.The linkage map contains 2795 SNP markers with the total length of 1832.9 cM and the average distance of 0.66 cM.A total of 19 QTLs were mapped on chromosomes A01,A03,A06,A07,A09,and C06.Twelve of them were identified under salinity stress with explained phenotypic variation from 4.9％ to 10.9％,and eight QTLs were related to drought stress with explained phenotypic variation from 3.8％ to 6.9％.The QTLs on A03 and A09 were located in close marker regions.Our results showed that the germination percentage of rapeseed is controlled by many minor-effect loci with great influence by environmental factors.Different genes are triggered in response to salinity or drought stress along with the stress duration.
国家科技期刊平台
NSTL
万方数据
维普
