四倍体栽培棉种产量和纤维品质性状的QTL定位

陆地棉和海岛棉是两个不同的四倍体栽培种 ,但在生产上各有其特点 ,陆地棉丰产性强 ,海岛棉纤维品质优良 ,利用其种间杂交群体定位产量和品质性状的QTL ,对于分子标记辅助的海岛棉优质纤维向陆地棉转移很有意义。以SSR和RAPD为分子标记 ,陆地棉与海岛棉杂种 (邯郸 2 0 8×Pima90 )F2 群体为作图群体 ,构建了一张含 12 6个标记的遗传图谱 ,包括 6 8个SSR标记和 5 8个RAPD标记 ,可分为 2 9个连锁群 ,标记间平均距离为 13 7cM ,总长1717 0cM ,覆盖棉花总基因组约 34 34% ;以遗传图 12 6个标记为基础 ,对F2 :3 家系符合正态分布的 10个农艺性状及纤维品质性状进行全基因组QTL扫描 ,结果发现 2 9个QTL分别与产量和品质性状有关。其中与衣指、籽指、皮棉产量、子棉产量、衣分等产量性状相关的QTL分别有 1、3、5、6和 1个 ,与纤维长度、整齐度、强度、伸长率和马克隆值等品质性状相关的QTL分别有 2、4、2、4和 1个。各QTL解释的变异量在 12 4 2 %～ 47 0 1%之间。其中比强度有关的 2个QTL能够解释的表型变异率分别为 34 15 %和 13 86 %。

Localization of QTLs for Yield and Fiber Quality Traits of Tetraploid Cotton Cultivar

Using SSR and RAPD as molecular markers,and the 69 F 2 families from a cross between Handan208 (Gossypium hirsutum) and Pima90 (Gossypium barbadense) as a mapping population,a linkage map comprising 126 markers was constructed.With an average spacing 13.7 cM between markers,the linkage map spanned 1 717.0 cM,which covers approximately 34.34% of the total recombinational length of cotton genome.Based on the linkage map and the F 2:3 phenotypic data,overall genome QTL screening was conducted by composite interval mapping method,then 29 QTLs related to cotton yield traits and fiber quality traits were found.There are 16 loci related to yield traits and 13 loci related to fiber quality.Particularly,two QTLs relevant to fiber strength were detected,which could explain phenotypic variance of 34.15% and 13.86%,respectively.