基于CSSL的水稻芽期耐盐性QTL定位

Mapping of QTLs for Bud-stage Salinity Tolerance Based on Chromosome Segment Substitution Line in Rice

水稻耐盐遗传位点的发掘可为其耐盐遗传机制的研究提供理论基础,为耐盐品种培育提供基因资源。利用一套以9311为背景亲本导入了日本晴染色体片段的染色体片段置换系(CSSL)为试验材料,对芽期耐盐性进行快速鉴定,并分析了耐盐QTLs。结果表明,9个CSSLs表现出显著耐盐性,经过遗传背景的高密度分子标记检测,利用代换作图方法定位到4个芽期耐盐相关QTLs,分别位于水稻第1,2,4和11号染色体上,命名为q SAT1、q SAT2、q SAT4和q SAT11,其中q SAT1在含4个重叠片段的CSSLs中被检测到,其余3个QTLs均在含2个重叠置换片段的CSSLs中被检测到,经比较发现4个QTLs与已克隆水稻耐盐基因均不在同一染色体区间,说明为新的耐盐基因候选位点。结果对进一步发掘和利用新的水稻耐盐QTL具有重要意义。

The identification of salt tolerant genetic loci in rice can provide study basis for the molecular mechanism of salt tolerance,and gene resources for improving salt tolerant cultivars. A set of chromosome segment substitution lines（ CSSLs） developed from two sequenced rice cultivars： the indica variety 9311 as the recipient and the japonica variety Nipponbare as a donor were used to detect for salt tolerance in bud stage quickly,and to locate QTLs related to salt tolerance. 9 CSSLs showed significant salt tolerance and 4 QTLs were mapped by genetic background detection based on high density molecular markers and the substitution mapping. These 4 QTLs located on rice chromosomes 1,2,4 and 11 chromosomes,designated as qSAT1,qSAT2,qSAT4 and qSAT11. qSAT1 was detected in 4 CSSLs containing over lapping fragments,while the other 3 QTLs were detected in 2 CSSLs. These QTLs were not included in the same chromosome interval as the cloned rice salt tolerance genes,and thus were described as new candidate gene loci associated with bud-stage salt tolerance. The results supplies important information for further exploration and utilization of new salt tolerant QTL in rice.