七叶树属种和种群的遗传多样性及遗传分化研究

Studies on Genetic Diversity and Differentiation of Species and Populations in Aesculus

利用RAPD标记对七叶树属7个种14个种群的遗传多样性和遗传分化进行了研究。结果显示:七叶树DNA提取以刚萌发的幼叶为佳,随着叶的生长,多糖干扰增加,成熟叶不适合基因组DNA提取。七叶树属种和种群之间基因多样性差异很大。在国产七叶树中,以陕西勉县中华七叶树种群和湖南新宁天师栗种群的基因多样性最高,达0. 261 3;甘肃康县中华七叶树种群和四川苍旺天师栗种群的基因多样性最低,分别为0. 189 2和0. 196 0。研究发现,除红花七叶树外,北美产的其它七叶树的基因多样性远低于国产七叶树,其中以欧洲七叶树的基因多样性最小,仅为0. 124 1。由于种群偏小,加之长期地理隔离,七叶树属种和种群间遗传分化巨大,种和种群间的遗传变异高达42. 21%。聚类结果可将天师栗分为中南部种群和北部种群两组,其北部种群与中华七叶树和浙江七叶树遗传距离较近。北美七叶树中红花七叶树与天师栗的中南部种群亲缘关系较近,而欧洲七叶树、黄花七叶树和光叶七叶树相互之间以及与3种国产七叶树间的亲缘地理较远。

Genetic diversity and differentiation of 7 species including 14 populations of Aesculus were studied. Results are as following: Considering the interruption of polysacoharide during the gowth of leaves, the germination period of young leaves is optimum opportunity to extract DNA. Studies indicated that there stands significant genetic diversity of species and population in Vesculus,In native Vesculus,the great genetic diversity lies in the populations of Aesculus chinensis Bunge in Mianxian, Shanxi Province and A.wilsonii Rehd in Xinning, Hunan Province, which arrives at 0.261 3,contrast to Aesculus chinensis Bunge in Kanxian, Ganshu Province and A.wilsonii Rehd in Cangwang, Sichuan Province, whose genetic diversity is the lowest. The studies also found that the genetic diversity of Vesculus in north America is dramatically lower than that of native Vesculus, besides A.pavia L..Taking into account the factors of geographical isolation and small population,the tremendous genetic differentiation exists in Vesculus reach 42.21%.Clustering analysis divides A. wilsonii Rehd into two groups:The south population and north population which has adjacent genetic distance with Aesculus chinensis Bunge and A.chinensis var. chekiangensis(Hu et Fang) Fang s. A.pavia L has close genetic relation with A.wilsonii Rehd population in the middle and south China, and A.hippocastanum L,A.octandra Marsh, A.glabra var. Willd have distant geographical relation.