棉花陆海渐渗杂交群体纤维品质性状的QTL定位

【目的】有效发掘利用海岛棉优异性状基因，拓宽陆地棉栽培种遗传基础。【方法】采用新疆主栽早中熟陆地棉品种新陆中60号为母本，与优质海岛棉品种新海41号为父本杂交，并以新陆中60号为轮回亲本构建出由151个BC₁F₁单株组成的回交群体，利用SSR分子标记和Join Map4.0软件构建遗传连锁图谱，采用复合区间作图法(CIM)对BC₁F₂纤维品质性状的进行QTL定位。【结果】构建的遗传连锁图谱包含52个多态性标记、14个连锁群，该图谱总长824 cM,覆盖棉花基因组的18.5%;最长的连锁群为150.3 cM,包含6个标记，最短的为0.3 cM,包含2个标记。检测到1个与纤维上半部平均长度相关的QTL,qFL-Chr14-1,定位在第14号染色体上，解释表型变异8.59%。【结论】筛选的与优质QTL位点相关SSR标记可应用于棉花优质分子标记辅助选择。

Analysis of QTL Mapping for Fiber Quality Traits in Introgression Lines Cotton

【Objective】 The research laid a foundation for the function research of high quality gene of long-staple cotton and broad genetic basis of upland cotton. 【Methods】 In this study, Xinjiang’s main early-middle-maturing upland cotton variety Xinluzhong 60 was used as the female parent and the high-quality island cotton variety Xinhai 41 was used as the male parent. Then, the BC₁F₂ population composed of 151 individual plants combined with Xinluzhong 60 as the recurrent parent was used as the mapping population to construct a genetic linkage map. We excavated stable QTLs related to fiber quality to provide a basis for molecular marker-assisted selection breeding. The linkage map was constructed with SSR markers by Join Map 4.0 software. The QTLs for fiber quality properties in BC₁F₂ populations were mapped by the inclusive composite interval mapping method with Ici Mapping. 【Results】 The map included 52 SSR loci and 14 linkage groups, covering 824 cM and accounting for 18.5% of the cotton genome. And the longest linkage group is 150.3 cM, containing 6 markers, and the shortest is 0.3 cM, containing 2 markers.A QTL related to the average length of the upper half of the fiber was detected, located on chromosome 14. It can be used as a candidate gene for functional research of cotton fiber quality genes in land-sea introgression lines. 【Conclusion】 The polymorphic markers selected in this study can assist early breeding selection.