首批海岛棉基因组来源的微卫星标记的分离、评价和定位

海岛棉(Gossypium barbadense)是世界上最重要的栽培棉种之一。海岛棉纤维品质优良，是优质棉的重要产源。为了研究海岛棉的遗传多样性，为海岛棉育种提供参考依据，从海岛棉遗传标准系中分离基因组来源的微卫星标记用于海岛棉遗传评价。采用两种方法分离微卫星标记，一是用ISSR (inter simple sequence repeat) 引物扩增Pima3-79，克隆测序后从中开发微卫星标记；二是利用简并引物扩增Pima3-79，克隆测序后从中开发微卫星标记。共挑选1 447个克隆，筛选出239个独立克隆。测序后得到214个单一序列，其中包含微卫星并可用于引物设计的序列70个，获得86对引物。86对引物用于扩增56个海岛棉材料和4个陆地棉材料，16对引物没有扩增，43对引物在所有材料中没有多态性；27对引物在海岛棉和陆地棉之间有多态性，19对引物在海岛棉中表现多态性。利用Jaccard相似系数和UPGMA方法进行聚类分析可以明显区分陆地棉和海岛棉，并且将海岛棉分为4类。14对引物在BC₁群体中表现多态性，产生14个位点。9个位点整合到BC₁连锁图的7个染色体上，4个位于A亚基因组，5个位于D亚基因组。海岛棉微卫星标记扩展了棉花微卫星标记，有助于海岛棉遗传多样性的研究，有利于棉花遗传图谱的进一步丰富。

Isolation, Characterization, and Mapping of Genomic Microsatellite Markers for the First Time in Sea-Island Cotton (Gossypium barbadense)

Sea-island cotton (G. barbadense) is one of the most important cultivated cotton species in the world. In order to explore the genetic diversity of this species, microsatellite loci were identified from G. barbadense cv. Pima3-79 (the genetic standard line). Microsatellite markers were developed using two different approaches: (i) cloning of ISSR amplified fragments and (ii) amplification using degenerate primers. Two hundred and thirty-nine unique clones were generated from 1447 recombinants, and 214 unique sequences were obtained. Eighty-six primer pairs were developed from 70 sequences that had flanking regions sufficient for primer design. The 86 SSR primer pairs were used to analyze 56 sea-island cotton accessions and 4 upland cotton cultivars, 16 primers had no amplification and 43 primers did not detect polymorphism between all the cultivars. Nineteen primers showed polymorphism between the sea-island cotton accessions. On the basis of Jaccard’s genetic similarity coefficient, these primers could distinctly distinguish sea-island cotton and upland cotton, and sea-island cotton accessions were separated into four groups. Nine interspecific polymorphic markers were mapped on the cotton genetic map with four mapped at A sub-genome and five at D sub-genome. These microsatellite markers will be useful for assessing the genetic diversity patterns within sea-island cotton as well as aiding in construction of genetic linkage maps.