甘蓝型油菜遗传图谱构建及苗期耐旱相关性状的QTL定位

Construction of a Molecular Genetic Map of Rapeseed(Brassica napus L.)and QTL Mapping of Its Drought Tolerance-Related Traits

以耐旱性差异较大的甘蓝型油菜三六矮和科里纳-2构建的重组自交系群体F2∶4家系为作图群体,通过SSR标记构建了包含15个连锁群的遗传连锁图谱,图谱总长762.95cM,相邻标记平均距离6.25cM.采用复合区间作图方法,在正常灌溉和干旱胁迫处理两种环境条件下,对苗期叶绿素质量分数、叶片相对含水量、叶片保水力、可溶性糖质量分数、丙二醛质量分数5个耐旱相关性状及其耐旱系数进行了QTL分析,共检测到8个QTL,分布在第1,3,5,12连锁群,单位点解释表型变异的6.6%-12.4%.在第5连锁群检测到叶绿素质量分数和叶片保水力的QTL重叠区域.

Recombinant inbred lines （RILs） F2：4 from the cross between 36-Ai and Kelina-2, two varieties of Brassica napus L. with striking difference in drought tolerance, were used as the mapping population, and a genetic linkage map was constructed using SSR markers, which contains 15 linkage groups. The total length of the map was 762.95 cM, with an average distance of 6.25 cM between adjacent markers. Composite interval mapping （CIM） with the linkage map was applied to identify the quantitative trait loci （QTL） associated with drought tolerance traits （chlorophyll content, soluble sugar content, malondialde- hyde content, relative water content and leaf water retention） at the seedling stage, and the drought tolerance coefficients were calculated. A total of 8 QTLs were found, distributed in Linkage groups 1, 3, 5 and 12. The single locus contribution to explain the phenotypic variance ranged from 6.6% to 12.4G. An o ver-lapping region of the QTLs of chlorophyll content and leaf water retention was observed in Linkage group 5.