红泡刺藤居群的遗传多样性研究

ISSR Analysis of Genetic Diversity of Rubus niveus Thunb.Populations

利用ISSR分子标记对红泡刺藤的12个居群共242个个体进行了遗传多样性分析。结果表明:(1)16个ISSR引物共扩增到257个位点,其中236个是多态性位点,占91.83%。(2)红泡刺藤居群具有较高水平的遗传多样性,在物种水平上,平均每个位点的多态位点百分率为97.50%,有效等位基因数为1.267,Nei’s遗传多样性为0.177,Shannon’s多态信息指数为0.296;居群水平上多态位点百分率为51.43%,有效等位基因数为1.205,Nei’s遗传多样性为0.127,Shannon’s多态信息指数为0.202。(3)居群间基因分化系数为0.281 5,AMOVA分析居群间遗传变异占总量的34.47%,二者结果相近,说明红泡刺藤居群间存在一定程度的遗传分化。居群内的遗传变异为65.53%,基因流为1.276 2。(4)Mantel检测显示居群间的遗传距离与地理距离不存在相关性。UPGMA聚类分析和二维主成分分析结果一致,红泡刺藤居群可分为2个居群组,即金沙江居群和维西居群为一个类群,其他居群为另外一大类,表明生态地理条件相似的居群优先集中。

Genetic diversity of 242 individuals from 12 natural populations of Rubus niveus Thunb. ,was as- sessed using ISSR markers. The results showed that sixteen primers produced a total of 257 amplified frag- ments,of which 236 （91. 83o//oo） are polymorphic. An extraordinarily high level of genetic diversity was showed in these populations. At species level, percentage of polymorphic loci PPB = 97. 50%, effective number of alleles （Ae） 1.267,Nei＇s gene diversity （H） 0. 177,and Shannon＇s information index （I） 0. 296. At population level, PPB= 51.43%,Ao = 1. 205, H= 0. 127, I= 0. 202. The level of genetic differentia- tion between populations is lower than that within populations. The coefficient of gene differentiation （Gst） between the populations is 0. 281 5, and the gene differentiation contributes to 34.47% of the total genetic variations between the populations and to 65. 53~ within the populations. The total gene flow （Nm） is 1. 276 2. While the Mantel test showed no significant correlation between genetic and geographic distances among population （r=0. 006 3,P=0. 278 0）. The results of UPGMA clustering analysis was basically i- dentical with principle coordinate analysis （PCA）. Jinshajiang （JSJ） population and Weixi （WX） popula- tion were clustered into one group. The other populations were clustered into another group in the dendro- gram. The results indicated that populations with similar ecological and geographical conditions were clus-tered firstly.