华北落叶松是我国华北地区营造针叶树丰产林的首选树种,我国自20世纪60年代开始营建华北落叶松种子园,现部分种子园已建至第3代。但选优导致的种子园亲子代群体间的遗传多样性水平变化情况并不清楚,其分子水平的群体遗传基础也不明确,造成高世代育种及造林工作中种质资源不清等问题。本研究利用10对EST-SSR引物,分析了河北省龙头山林场华北落叶松良种基地种子园中1代、2代、3代优树群体的遗传多样性。每对引物的等位位点数为2-5个不等。1、2、3代的平均有效等位位点数分别为1.9204个、1.81个、2.0693个,Shannon指数分别为0.7127、0.7052、0.7908,且群体中杂合子过量。结果表明,1-3代种子园群体遗传多样性水平没有明显的差异,子代群体与亲代群体间遗传分化较小,遗传变异主要存在于每代群体内,而非世代群体间。
Larix principis-rupprechtii Mayr. is one of the most proper conifer species for forestation in north China. Seed orchards of Larix principis-rupprechtii Mayr. have been built since 1960 s in China,and some of which have already contained three generations. However,lack knowledge of genetic variations after selection on molecular level causes some unclearness in breeding and forestation. 10 EST-SSR primers were used in this study to analysis the genetic diversity among three generations in the seed orchard in Hebei. Each primer had 2-5 loci. The numbers of average effective loci for the 1^st,2^nd,and 3^rdgenerations were 1. 92,1. 81,and 2. 07. Shannon index were 0. 7127,0. 7052,and 0. 7908. Heterozygote excessed in the populationgs. The value of Fst was low,which showed that genetic differences were mainly occurred in one generation rather than among generations.