【摘要】 纤维长度作为棉花纤维品质的核心指标，其分子标记的开发对加速育种进程具有重要意义。本研究基于混合分组分析结合全基因组测序(BSA-seq)的定位开发了与棉花纤维长度相关的分子标记GhCRK26-1931 SNP,并系统评价了其应用价值。通过对512份棉花品种(系)的竞争性等位基因特异性PCR(KASP)基因分型和表型分析发现，供试材料表现出丰富的遗传多样性，海岛棉与陆地棉回交群体纤维极端材料、陆地棉种质材料和海岛棉种质材料纤维长度存在明显表型变异，变异系数范围为3.48%～9.65%,基于纤维长度等表型数据的聚类分析将材料划分为4大类群。验证试验结果显示，GhCRK26-1931 SNP分子标记在海岛棉与陆地棉回交群体亲本系9和新海16中的基因分型结果与BSA-Seq数据完全一致：系9为TT基因型，新海16为CC基因型；在60份海岛棉与陆地棉回交群体极端材料中，CC基因型(37份)和TT基因型(23份)的纤维长度存在显著差异(P<0.05),且TT基因型纤维长度均值小于CC基因型；进一步在305份陆地棉(Gossypium hirsutum)和145份海岛棉(Gossypium barbadense)种质材料中均观察到类似规律，TT基因型材料的纤维长度均值小于CC基因型(P<0.05)。综上，GhCRK26-1931 SNP分子标记可有效用于棉花纤维长度的选择育种，其中CC基因型对纤维长度具有正向调控效应。本研究不仅为优质棉花品种的选育开辟了新途径，也为棉花纤维品质的分子标记辅助选择提供了可靠工具。更多还原

【Abstract】 As a core indicator of cotton fiber quality,fiber length plays a crucial role in accelerating the breeding process through the development of its molecular markers.In this study,a molecular marker(GhCRK26-1931 SNP) associated with cotton fiber length was developed via localization based on bulked segregant analysis combined with whole-genome sequencing(BSA-Seq),and its application value was systematically evaluated.Competitive allele-specific PCR(KASP) genotyping and phenotypic analysis were conducted on 512 cotton varieties(lines).The results showed that the tested materials exhibited rich genetic diversity,and there were significant phenotypic variations in fiber length among extreme fiber materials of Gossypium hirsutum-Gossypium barbadense backcross populations,G.hirsutum germplasm materials,and G.barbadense germplasm materials,with the coefficient of variation ranging from 3.48% to 9.65%.Cluster analysis based on phenotypic data such as fiber length divided the materials into four major groups.Verification test results indicated that the genotyping results of GhCRK26-1931 SNP molecular marker in the parental Line 9 of the G.hirsutum-G.barbadense backcross populations and Xinhai16 were completely consistent with the BSA-seq data:Line 9 had the TT genotype,while Xinhai 16 had the CC genotype.Among60 extreme materials of the G.hirsutum-G.barbadense backcross populations,there was a significant difference in fiber length between the CC genotype(37 materials) and the TT genotype(23 materials)(P<0.05),and the average fiber length of materials with the TT genotype was shorter than that of materials with the CC genotype.Furthermore,a similar pattern was observed in 305G.hirsutum materials and 145 G.barbadense materials:the average fiber length of materials with the TT genotype was still shorter than that of materials with the CC genotype(P<0.05).In conclusion,the GhCRK26-1931 SNP molecular marker can be effectively used in the selective breeding for cotton fiber length,and the CC genotype has a positive effect on improving fiber length.This study not only opens up a new avenue for the breeding of high-quality cotton varieties but also provides a reliable tool for marker-assisted selection of cotton fiber quality.更多还原