黑籽重楼种内AFLP遗传多样性及遗传分化研究

AFLP analysis on genetic diversity and differentation of Paris thibetica

以四川瓦屋山、峨眉山和彭州3个地区的黑籽重楼原变种居群及峨眉山、彭州2个地区的无瓣黑籽居群为供试材料，用筛选出的4对引物，对5个群体共计74个个体进行AFLP分析，每对AFLP引物扩增出61-78条多态带，共得到235条多态带．黑籽重楼遗传多样性较高，物种水平的多态带百分率PPB为81．88％，Nei’s基因多样性指数H为0．2490，Shannon多样性指数I为0．3867，居群间基因流为1．6870；在变种水平上，黑籽重楼原变种PPB为78．40％，Nei’s基因多样性指数H为0．2849，Shannon多样性指数I为0．4237；无瓣黑籽的PPB为63．07％，Shannon多样性指数I为0．3603，Nei’s基因多样性指数H为0．2439．黑籽重楼种下的两个变种间的遗传分化系数Gst为0．0726，遗传分化指数PHIst为13．33％．聚类结果无瓣黑籽重楼和黑籽重楼原变种分别分成两支．总而言之，黑籽重楼物种水平上有丰富的遗传多样性，居群内遗传分化大于居群间，居群间的相似性系数很大，但种下的两个变种间有一定的遗传分化．

AFLP was utilized to screen for genetic variation within Paris thibetica. AFLP analysis using 4 pairs of AFLP primers was carried out on 74 different samples from five populations of Paris thibetica located at EMEI Mountain, WAWU Mountain, and Pengzhou in Sichuan Province. Each primer pair produced 61-78 bands, and a total of 287 discernible DNA fragments were generated with 235 polymorphic bands （81.88%）. In Species level, the percentage of polymorphic bands （PPB） was 81.88% ; Shannon＇s information index （I） was 0. 3867. Nei＇s genetic diversity was 0. 2490. Gene flow （Nm） was high （1.6870）. The genetic identities between populations were similar （ IN = 0. 8877-0.9410）. Genetic differentiation （Gst） among 5 populations detected by Nei＇ s genetic diversity analysis was 0. 2286. At variety level, the estimates of P. thibetica var. thibetica were PPB = 78.40 %, H = 0. 2849, I = 0. 4273, and the estimates of P. thibetica var. apetala were PPB = 63.07 %, H = 0. 2439, I = 0. 3603. As for P. thibetica, genetic differentiation coefficient among varieties （Gst） was 0. 0726. According to the UPGMA cluster analysis, the differentiation of 2 varieties were significant. Two varieties of Paris thibetica were divided into two groups in the of Got and PHIst dendrogram, in which. Samples from the same population and varieties mostly clustered in the same cluster. But the result indicated that there were relatively low genetic differentiation among the two varieties, but high genetic diversity in species level.