滇牡丹天然居群的遗传多样性分析

Genetic Diversity Analysis of Natural Populations in Paeonia delavayi

以云南中部及西北部的6个滇牡丹（Paeonia delavayi）天然居群为研究对象,进行株高、新枝长等9个表型性状的表型多样性分析和ISSR分析。结果表明：9个表型性状变异幅度为0.9%-39.8%,平均值达到了18.9%;居群间生殖器官的变异较大,居群内营养器官更容易产生变异。利用居群间欧式距离进行聚类分析,6个居群聚为4个类群,没有与实际地理位置相吻合,说明表型特征的性状与地理距离的相关性不大。遗传多样性分析结果表明：利用筛选得到的10条引物,在取自6个自然居群、180个个体中,检测到56个多态位点。在居群水平上,多态位点百分率（PPB）为60.2%,Nei＇s基因多样性指数（H）和Shannon＇s信息指数（I）分别为0.281和0.414。在物种水平上,Nei＇s基因多样性指数（H）和Shannon＇s信息指数（I）分别为0.409和0.596。居群间的遗传分化系数（Gst）达0.319。结果显示,表型性状在居群间和居群内均存在广泛变异。滇牡丹遗传多样性水平较高,居群间遗传分化较大,滇牡丹并不濒危。

The diversity of nine phenotypic traits and ISSR analysis in six natural populations of Paeonia delavayi were studied in this work. The results revealed that abundant variations of all phenotypic traits occurred among and within populations. The coefficient of variation（ CV） of nine phenotypic traits ranged from 0. 9% to 39. 8%,with18. 9% of the mean value. Variation of reproductive organs was larger than that of vegetative ones among populations,while variation of vegetative organs was easily occurred compared with reproductive organs variation within populations. Euclidean clustering analysis showed that the six natural populations could be clustered into four groups. It was indicated that variation of phenotypic traits did not correspond to geography distance. 56 ISSR polymorphic loci were amplified from 180 individuals of 6 natural populations by 10 useful primers. Of them,the value of PPB,H and I was 60. 2%,0. 281 and 0. 414,respectively,at population level,while the value of H and I was 0. 409 and 0. 596,respectively at species level. The Gst（ 0. 3119） indicated a high degree of genetic differentiation occurred among P. delavayi populations. The results of genetic diversity study,combined with field survey and previous investigations suggest that P. delavayi is not endangered.