Institute of Cash Crops, Hubei Academy of Agricultural Sciences, Wuhan, China; Key Laboratory of Cotton Biology and Breeding in the Middle Reaches of the Changjiang River (Wuhan), Ministry of Agriculture, Wuhan, P. R. China.
Key Laboratory of Cotton Biology and Breeding in the Middle Reaches of the Changjiang River (Wuhan), Ministry of Agriculture, Wuhan, P. R. China.
PLoS One. 2015 Jan 30;10(1):e0118073. doi: 10.1371/journal.pone.0118073. eCollection 2015.
Detecting QTLs (quantitative trait loci) that enhance cotton yield and fiber quality traits and accelerate breeding has been the focus of many cotton breeders. In the present study, 359 SSR (simple sequence repeat) markers were used for the association mapping of 241 Upland cotton collections. A total of 333 markers, representing 733 polymorphic loci, were detected. The average linkage disequilibrium (LD) decay distances were 8.58 cM (r2 > 0.1) and 5.76 cM (r2 > 0.2). 241 collections were arranged into two subgroups using STRUCTURE software. Mixed linear modeling (MLM) methods (with population structure (Q) and relative kinship matrix (K)) were applied to analyze four phenotypic datasets obtained from four environments (two different locations and two years). Forty-six markers associated with the number of bolls per plant (NB), boll weight (BW), lint percentage (LP), fiber length (FL), fiber strength (FS) and fiber micornaire value (FM) were repeatedly detected in at least two environments. Of 46 associated markers, 32 were identified as new association markers, and 14 had been previously reported in the literature. Nine association markers were near QTLs (at a distance of less than 1-2 LD decay on the reference map) that had been previously described. These results provide new useful markers for marker-assisted selection in breeding programs and new insights for understanding the genetic basis of Upland cotton yields and fiber quality traits at the whole-genome level.
检测增强棉花产量和纤维质量性状并加速育种的 QTL（数量性状位点）一直是许多棉花育种者关注的焦点。在本研究中，使用 359 个 SSR（简单序列重复）标记对 241 个陆地棉群体进行了关联作图。共检测到 333 个标记，代表 733 个多态性位点。平均连锁不平衡（LD）衰减距离分别为 8.58cM（r2>0.1）和 5.76cM（r2>0.2）。使用 STRUCTURE 软件将 241 个群体分为两个亚群。采用混合线性模型（MLM）方法（包括群体结构（Q）和相对亲缘关系矩阵（K））分析了从四个环境（两个不同地点和两年）获得的四个表型数据集。在至少两个环境中重复检测到与每株棉铃数（NB）、铃重（BW）、皮棉率（LP）、纤维长度（FL）、纤维强度（FS）和纤维微绒值（FM）相关的 46 个标记。在 46 个相关标记中，有 32 个被鉴定为新的关联标记，有 14 个在文献中已有报道。9 个关联标记位于先前描述的 QTL 附近（参考图谱上的 LD 衰减距离小于 1-2）。这些结果为在育种计划中进行标记辅助选择提供了新的有用标记，并为理解陆地棉产量和纤维质量性状的全基因组遗传基础提供了新的见解。
