中文摘要：

用基因组扫描的方法，利用棉花9个连锁群上的79个微卫星标记（Simple sequence repeat，SSR），对收集的204份陆地棉品种（系）组成的品种资源群体进行群体结构和连锁不平衡（Linkage disequilibrium，LD）分析。结果表明：本研究群体可划分为3个群体，其中两个群体分别由3个亚群体组成。群体中，47％的标记位点之间可以观察到显著的LD（P≤0．05）。LD在遗传距离小于120cM范围内普遍存在。在决定系数12≤0．05时，LD在0．01单位的平均衰减距离为29．7cM，在，≥0．05的条件下能观察到的LD最大遗传距离为31．4cM，在，≥0．1时能观察到LD的最大遗传距离缩小到3．4cM。群体的连锁不平衡状况表明本研究群体可用于重要育种性状的关联分析。

英文摘要：

Population structure and LD （Linkage disequilibrium）of 204 upland cotton accessions were analyzed with 79 SSR （Simple sequence repeat） markers located on nine chromosomes. Analysis of population genetic structure based on SSR data revealed that this population could be divided into three groups, two out of which were composed of three subgroups, respectively. 47% of the SSR loci pairs showed LD at significant level of P ≤ 0.05. The maximum genetic distance of LD could be observed extended to 120 cM. The LD average decay distance was 29.7 cM at r2≤ 0.05. Genome wide LD reduced to 3.4 cM at r2≥ 0.1, providing evidence of the potential for association mapping of important traits in cotton breeding program.