不同生态类型龙眼种质亲缘关系的ISSR分析

Analysis on Genetic Relations in Different Ecotypes of Longan(Dimocarpus longan Lour.) Germplasm Resources by ISSR Markers

利用ISSR分子标记技术对不同生态类型的39份龙眼种质进行亲缘关系分析。研究结果表明,从100条ISSR引物中筛选出12条重复性好、条带清晰的引物,对39份龙眼种质基因组DNA进行扩增,得到152个位点,其中多态性位点117个,多态性比例为76.97%。供试龙眼种质间遗传相似系数变幅为0.57～0.92,说明ISSR标记能够揭示材料间较高的遗传多样性。UPGMA聚类结果表明,在0.65相似水平可以将39份龙眼种质分为3个类群,类群Ⅰ均为来自中国的南亚热带生态型龙眼;类群Ⅱ包括石硖和大乌圆2个南亚热带生态型龙眼品种,以及热带生态型龙眼四季蜜类型的品种和单株;类群Ⅲ包括来自越南和泰国的龙眼种质。不同生态类型对龙眼的亲缘关系影响不大,热带生态型和南亚热带生态型龙眼相互聚在一起,说明两种不同生态类型龙眼具有较多相同的遗传背景。本试验结果将有助于进一步开展龙眼的分类、遗传与进化研究。

ISSR markers were used to study genetic diversity and relationship of different ecotypes of longan germplasm resources. The results showed that 12 primers from 100 ISSR primers were selected for amplify the ge- nome DNA of 39 materials. Totally 152 ISSR loci including 117 polymorphic loci were produced, with a polymor- phism rate of 76.97%. The genetic similarity coefficients among 39 different ecotypes longan materials were be- tween 0.57 and 0.92. That means ISSR markers can reveal the genetic diversity of these tested materials. All of the cuhivars could be separated into three groups at about 0.65 similarity value with UPGMA, inchuding a group of south subtropical ecotype longan from China; a group of south subtropical ecotype longan Shixia and Dawuyuan,and tropical ecotype longan Sijimi genotype,and a group of longan from Vietnam and Thailand. It was also showed that the genetic relationship has a higher level of genetic background in different ecotypes of longan. These results will provide much more useful information for studing classification, genetics, and evolution of longan germplasm re- sources.