小麦苗期耐盐相关性状的QTL分析

MAPPING QTL FOR SALT TOLERANT TRAITS IN WHEAT

以小麦敏盐品种太空6号和耐盐品种德抗961杂交形成的R和F2：3家系为试验材料，选取小麦8条染色体上的321对SSR引物进行亲本间多态性的筛选，在太空6号和德抗961之间表现多态性的SSR引物为52个，位点为54个，其中barc172和era2121两个引物分别有两个多态性位点。对这54个位点进行连锁分析，构建了包含42个SSR标记、覆盖小麦基因组8条染色体的遗传连锁图，共704．5eM，标记间平均间距为16．8cM。采用复合区间法进行耐盐QTL分析．，对于4个性状共定位到6个QTL，分别位于5A，5B，5D染色体。对于发芽率，检测到1个QTL，位于染色体5D上，在标记efd40～gwm182之间，贡献率为7．68％，表现加性效应；对于苗高，检测到2个QTL，分别位于染色体5D和5A上，在标记gwm182～wmc215及barc141～wmc415之间，贡献率分别为9．3％和8．14％，分别表现为显性和部分显性；对于根长，检测到2个QTL，均位于染色体5B上，在标记gwm234与wmc326及barc140与barc142之间，贡献率分别为8．74％和8．40％，分别表现为部分显性和超显性；对于鲜重，检测到1个QTL，位于染色体5D上，在标记wmc215～efd29之间，贡献率为12．60％，表现超显性。与所得的QTL位点距离较近的SSR标记，如barc141等，可望为耐盐小麦品种的分子标记辅助选择提供参考信息。

In order to identify QTLs associated with salt-tolerance in wheat, F2 and F2：3 populations from the cross between the high yield variety Taikong 6 and salt tolerant variety Dekang 961 were produced. A total of 42 SSR markers were used to construct a linkage map, covering 704.5 cM of 8 wheat linkage groups, with an average distance of 16.8 cM. With the method of composite interval mapping （CIM）, 6 QTLs were detected. 1 QTL for germination rate was detected on chromosome 5D, which could explain 7.68% of phenotypic variation and show additive effect, flanked by SSR markers cfd40 and gwm182. 2 QTLs for seedling height were detected on chromosome 5D and 5A respectively, which could explain 9.30% and 8.14 % of phenotypic variation and show dominant effects and partially dominant effects, flanked by SSR markers gwm182 and wmc215, barc141 and wmc415, respectively. 2 QTLs for root length were detected on chromosome 5B, which could explain 8.74% and 8.40% of phenotypic variation and show partially dominant and super effects, flanked by SSR markers gwm234 and wmc326, barcl40 and barc142, respectively. 1 QTL for fresh weight was detected on chromosome 5D, which could explain 12.60% of phenotypic variation and show super dominant effects, flanked by SSR markers wmc215 and cfd29. The molecular markers identified in this study could be helpful for marker-assisted selections and pyramiding salt-tolerance genes in wheat breeding programs.