与棉花纤维强度连锁的主效QTL应用于棉花分子标记辅助育种

The Major QTLs linked to Fiber Strength for Cotton Breeding Program by Molecular Marker Assisted Selection

本文以黄河流域广泛种植的转基因抗虫棉品种sGK321和sGK9708(中41)为轮回亲本,分别与优质丰产品种太121和高纤维品质渐渗种质系7235杂交的F1代材料杂交并回交,配置了杂交回交组合两套,运用与一个已定位的高强纤维QTL紧密连锁的2个SSR标记,通过对这两套杂交组合的不同世代群体的数据进行分析研究,在sGK321×[(Tai121×7235)×sGK321]组合的F2群体、F2:3群体和sGK9708×[(Tai121×7235)×sGK9708]组合的F2群体、F2:3群体中,有/无标记个体的平均纤维强度分别为29.78cN/tex//28.19cN/tex、29.35cN/tex//27.97cN/tex和29.74cN/tex//27.65cN/tex、29.12cN/tex//27.33cN/tex,差异都达到了极显著水平。本研究表明了此高强纤维主效QTL在不同的遗传背景,经过多代杂交、回交和自交后,能够稳定遗传而且QTL的效应稳定;利用此高强纤维主效QTL的分子标记进行辅助选择提高棉花纤维强度效果是显著的。可以在棉花的苗期或早期世代进行分子标记辅助选择,这为快速有效地改良棉花纤维品质、培育棉花新品种新品系提供了理论依据。并运用此项技术结合其它手段进行优质、抗虫等基因的聚合育种研究,快速有效地改良现有的陆地棉推广品种,创造高产、优质、抗虫棉花新材料或新品系。

sGK9708 and sGK321, two transgenic insect-resistant cotton cultivars with high yield commercially planted in the Yellow River Valley, Tai121, a high yield variety widely planted in the Yangtze Valley, and 7235, a G. anomalum introgression high fiber quality line, were used as parents to develop two backcross-self combina- tions of sGK321 ×[（Tai 121 ×7235）×sGK321 ] and sGK9708×[（Tail 21 ×7235）×sGK9708]. Using the two SSR markers linked tightly with the fiber high strength major QTL from 7235, the DNA from sGK321 ×[（Tai121 ×7235）× sGK321] F2 population and sGK9708×[（Tai121×7235）×sGK9708] F2 population were screened, and the marker re suits and fiber quality data from F2 and F2：3 populations of two combinations were analyzed. There were significant differences in the mean of fiber strength with and without marker, 29.78 cN/tex//28.19 cN/tex, 29.35 cN/tex//27.97 cN/tex, 29.74 cN/tex/27.65 cN/tex, 29.12 cN/tex/27.33 cN/tex, respectively for F2 and F2：3 populations of sGK321×[（Tai121×7235）×sGK321] and F2 and F2：3 populations of sGK9708×[（Tai121×7235）×sGK9708]. The results showed that the genetic effect of the QTL was stable and significant in different genetic backgrounds, different segregating generations and different environmental conditions. So it is possible and efficient to increase fiber strength through the MAS in seedling stage. In the meanwhile, we pyramided high fiber strength gene and insect-re-sistant gene by MAS and other methods and attained 9 lines with super fiber quality and resistance to insects.