小麦苗期耐盐相关性状的QTL分析

以小麦敏盐品种太空6号和耐盐品种德抗961杂交形成的F2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cfa2121两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704.5cM,标记间平均间距为16.8 cM。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cfd40~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~cfd29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。

MAPPING QTL FOR SALT TOLERANT TRAITS IN WHEAT

In order to identify QTLs associated with salt-tolerance in wheat,F_2 and F_(2:3) 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,barc140 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.