陆地棉优质纤维QTL的分子标记筛选及优质来源分析

利用陆地棉优质品系7235、渝棉1号做亲本, 以7235 × 渝棉1号的F2与F2:3分离群体为材料, 开展不同来源棉花高强纤维QTL微卫星标记筛选, 为进一步进行优质纤维QTL聚合育种提供基础。通过5 514对SSR引物对亲本进行多态性筛选, 获得117个多态性标记, 用其中80个标记构建了总长为1 147.8 cM的遗传图谱; 应用复合区间作图法分析了该组合的F2单株和F2:3家系纤维品质性状, 共检测到36个纤维品质数量性状基因座(QTL), 其中与纤维长度、比强度、细度、伸长率及整齐度相关的QTL各6、8、7、8和7个, 分别解释各性状表型变异的3.4%~14.4%、5.0%~42.4%、6.5%~11.7%、5.1%~19.4%和6.9%~14.0%。通过分析来源于7235和渝棉1号高强QTL的染色体分布, 表明两亲本在D7、D8、D9染色体上都存在控制纤维比强度的QTL, 其中存在于D7和D8染色体上来自双亲的QTL紧密连锁, 成簇分布在染色体上的一定区间内。而在D7和D9染色体上也发现双亲完全相同的优质QTL, 其优质供体可能来自陆地棉优质品系PD4381。进一步分析了获得的QTL在聚合育种中的应用潜力。

Molecular Tagging and Source Analysis of QTL for Elite Fiber Quality in Upland Cotton

With the development and application of molecular biology technology in recent years, several genetic maps developed from different combinations have been constructed and lots of QTL controlling fiber quality or yield components detected, which makes the breeding procedure more effective, immediate and time-saving. In this paper, both F₂ and F_2:3 populations were constructed using two elite upland cotton (Gossypium hirsutum L.) strains (variety), 7235 and Yumian 1 as parents. Linkage analysis with SSR molecular markers revealed that 80 loci were mapped into 19 linkage groups that covered 1 147.8 cM genetic distance. A total of 36 QTLs were detected by composite interval mapping method, including 6 for fiber length, 8 for fiber strength, 7 for micronaire value, 8 for fiber elongation and 7 for fiber uniformity; and explained 3.4%–14.4%, 5.0%–42.4%, 6.5%–11.7%, 5.1%–19.4%, and 6.9%–14.0% of the corresponding phenotypic variations, respectively. Analysis of QTL distribution indicated that D7, D8, and D9 chromosomes were enriched with QTLs controlling fiber strength in both parents, among them those existed in D7 and D8 chromosomes were closely linked and two QTLs controlling fiber strength located respectively in D7 and D9 chromosomes were in the complete same position, which could be related with that both 7235 and Yumian 1 bear the pedigree of elite fiber accession PD4381. The utilization potential of the QTL of super quality in the pyramiding breeding was also discussed.