海岛棉CSSLs分子评价及纤维品质、产量性状QTL定位

本课题组前期以陆地棉中棉所8号(CCRI8)为轮回亲本, 海岛棉Pima 90-53为供体亲本培育了一套陆地棉中棉所8号为背景的海岛棉染色体片段置换系(CSSLs), 本研究利用SSR标记对该置换系群体BC₃F₅进行基因型检测, 在3个不同环境下(河北保定、青县和新疆轮台)鉴定其纤维品质和产量相关性状并进行QTL定位。该置换系群体包含182个家系, 置换片段数在1~15个之间, 平均为6.6个; 导入片段长度在0.7~83.2 cM之间, 平均长度为16.8 cM; 置换片段总长度20 249.6 cM; 背景回复率在92.3%~99.6%之间, 平均为96.2%。共检测出59个相关的QTL, 其中与纤维品质性状相关的41个, 单个QTL的贡献率为1.27%~26.66%; 与产量性状相关的18个, 单个QTL的贡献率为2.03%~19.38%; 检测到14个稳定的QTL, 其中4个马克隆值和2个纤维伸长率相关的稳定QTL增效基因均来自高值亲本海岛棉Pima 90-53, 2个铃重相关的稳定QTL增效基因来自高值亲本陆地棉中棉所8号。研究结果为深入开展纤维品质和产量性状的QTL精细定位、QTL间互作和分子育种提供了理论依据。

Molecular Evaluation for Chromosome Segment Substitution Lines of Gossypium barbadense and QTL Mapping for Fiber Quality and Yield

In the previous study, we developed a set of chromosome segment substitution lines (CSSLs) using G. hirsutum CCRI8 as the recipient parent and G. barbadense Pima 90-53 as the donor parent. In this study, we genotyped the BC₃F₅ generation of CSSLs with SSR markers, conducted QTL mapping for the fiber quality and yield traits and identified the stable QTLs in three different environments (Baoding, Qingxian, Luntai). The substituted segment number of the 182 CSSLs varied from one to fifteen, averaged 6.6. The length of introgressed segments ranged from 0.7 cM to 83.2 cM, and averaged 16.8 cM. The total length of the substituted fragment was 20 249.6 cM, background recoverage rate varied from 92.3% to 99.6%, and the average background recoverage rate was 96.2%. Fifty-nine QTLs related to fiber quality and yield traits were detected. Among them, 41 QTLs were related to fiber quality traits and each QTL explained 1.27% to 26.66% of the phenotypic variation. Eighteen QTLs for fiber yield-traits including boll weight and lint percentage were detected and each QTL explained 2.03% to 19.38% of the phenotypic variation. Fourteen stable QTLs were detected in multiple environments. Among them, four QTLs related to micronaire value and two QTLs related to fiber elongation both had enhancing alleles from G. barbadense Pima 90-53. Two boll weight QTLs had enhancing alleles from G. hirsutum CCRI8. The results provide a theoretical basis for QTL fine mapping, QTL interaction and molecular breeding for fiber quality and yield traits.