基于SRAP分子标记的小果油茶遗传多样性分析

Analysis of Camellia meiocarpa Genetic Diversity Based on SRAP Markers

利用SRAP分子标记,从126对引物组合中筛选出11对引物,对小果油茶全分布区的19个居群514个样品进行遗传多样性分析。结果表明:11对引物组合总共扩增出226条谱带,平均每对引物组合扩增20.55条谱带,其中多态性条带为226,占条带总数的100%。19个居群的遗传距离为0.0216～0.1645,显示了较近的亲缘关系。UPGMA聚类结果表明,除了福建6个居群和江西3个以外,其余地理位置相近的居群未能聚在一起。多态性比率(PPB)、Nei’s基因多样度(H)及Shannon信息指数(I)变化幅度分别为84.96%～95.58%,0.3213～0.3887及0.4732～0.5676;从物种层次来看,PPB,H,I分别为100%,0.4223及0.6126,揭示小果油茶具有丰富的遗传多样性。AMOVA分子变异分析显示,在小果油茶总的遗传变异中,居群内占86.58%,而居群间仅占13.42%。

In the present study, 11 pairs of SRAP primers were selected from 126 combinations and applied to analyze genetic diversity of 514 samples from 19 populations of Camellia meiocarpa in its whole distribution area. The results showed that a total of 226 fragments was amplified, and the average amplified fragments of each primer pair were 20.55. There were 226 polymorphic bands, and the percentage of polymorphie bands （PPB） was 100%. The genetic distance between 19 populations ranged from 0. 021 6 to O. 164 5, indicating that their genetic relationship was very close. The UPGMA clustering showed that the all populations, apart from 3 populations of Jiangxi Province and 6 populations of Fujian Province, were not clustered together according to their geographical locations. The PPB, Nei＇ s genetic diversity index（H） and Shannon＇ s information index（I） of different populations were 84.96% -95.58% , 0. 321 3 -0. 388 7 and O. 473 2 - 0. 567 6, respectively. At species level, the three parameters were 100% , 0. 422 3 and 0. 612 6, respectively, showing rich genetic diversity at both population and species levels of C. meiocarpa. The molecular variance analysis displayed the genetic variation mainly existed within populations （86.58%） and few among them （ 13.42% ） in all genetic variation.