新疆自育陆地棉品种SSR遗传多样性分析

Genetic Diversity Analysis on Local Upland Cotton Cultivars in Xinjiang Based on SSR Markers

利用SSR标记对94份新疆自育陆地棉品种的基因组进行分析，研究新疆陆地棉品种的遗传多样性。结果表明，从分布于棉花全基因组的206对SSR标记中筛选出54对具有稳定多态性的引物，共检测出153个多态性位点，每对引物的等位变异为2-6个，平均为2．93个；基因型多样性（硝）变幅为0．0439～0．7149，平均为0．4491；引物多态信息含量（PIC）为0．0430～0．6640，平均为O．3831。表明SSR标记在品种间可以反映较丰富的遗传多样性信息。94份品种间成对遗传相似系数变幅为0．3846～0．9835，71．9％的品种相似系数在0．601～0．800内，反映出新疆陆地棉品种间的遗传相似性相对较高。根据UPGMA聚类分析，在阈值为O．63时，将94份品种划分为2个类群，说明新疆陆地棉品种间遗传关系相对简单，品种的遗传基础相对狭窄，品种遗传组分差异较小，总体上遗传多样性不够丰富；分子聚类结果与品种本身遗传系谱背景和演变趋势吻合度较高，符合品种的真实特性。研究表明，自育品种在分子水平上差异不大，需要努力拓宽品种选育的遗传基础。

Xinjiang, the largest prior cotton production region in China, has made remarkable genetic improvement in upland cotton （Gossypium hirsutum L.）. There has been a substantial raise in yield potential, cotton-planting area and total production in Xinjiang since 1970s. The new upland cotton cultivars have contributed a lot to yield increase, in which Xinjiang-bred upland cotton varieties play an important role in cotton production in both Northern and Southern Xinjiang. However, seldom research on genetic basis of genetic diversity and pedigree relationship has been evaluated in upland cotton varieties in Xinjiang so far. This study aimed to reveal the genetic diversity of 94 upland cotton varieties in Xinjiang by genome analysis using SSR markers. The results indicated that SSR molecular markers could be employed in revealing the genetic diversity. One hundred and fifty-three polymorphic loci were detected by amplified with 54 pairs of primers with allelic variation of 2-6 per primer pair and the average of 2.93. The genotypic diversity （/-/＇） spanned from 0.0439 to 0.7149, with the average of 0.4491. The PIC value ranged from 0.0430 to 0.6640, and the average was 0.3831. The coefficients of genetic similarity among 94 tested cultivars varied from 0.3846 to 0.9835. And more than 71.9% of similarity coefficients fell into the interval of 0.601-0.800, indicating that the genetic similar- ity among the cultivars was high, whereas the genetic diversity might not be abundant. According to UPGMA cluster analysis, 94 tested cultivars were divided into two clusters when the threshold valve was given as 0.63, showing the relatively simple genetic relationship among the upland cotton varieties in Xinjiang, and relatively low genetic diversity and narrow genetic basis. The re- sults of molecular clustering on genetic diversity of upland cotton coincided in large degree with the pedigree relationship. In con-clusion, there is no much difference on molecular level among Xinjiang-bred upland cotton varieties. Materials with much wider genetic backgrounds are suggested to be used to diversify the genetic basis of cotton varieties in Xinjiang.