狭边大叶藓(Rhodobryum ontariense)遗传多样性的ISSR分析

狭边大叶藓Rhodobryum ontariense(Kindb.)Paris]为真藓科大叶藓属植物,具有治疗心血管疾病的功效。本研究选用ISSR分子标记对分布于河北、河南、四川和陕西四省的9个狭边大叶藓自然居群的遗传多样性进行研究,目的在于揭示狭边大叶藓居群的遗传结构和遗传多样性水平,为其保护和合理开发利用提供科学依据。用8个ISSR引物对9个居群共58个样品进行扩增,共获得47条清晰的扩增位点。POPGENE分析表明,狭边大叶藓居群遗传多样性水平较低(多态性位点比率为37.75%,Nei’s基因多样性为0.153 0,Shannon’信息指数为0.222 8,遗传分化指数Gst为0.299 7,居群间的基因流为1.168 2)。AMOVA分析表明,大多数遗传变异(84.07%)存在于居群内,15.93%的遗传变异存在于居群间(Φst=0.159 3)。UPGMA聚类分析表明,狭边大叶藓居群遗传距离和地理距离没有相关性(r=0.404 95,p=0.979 1)。

Genetic diversity in a medicinal plant species: Rhodobryum ontariense(Bryaceae), detected by ISSR

The present study focused on the mosses species,Rhodobryum ontariense(Kindb.) Paris(Bryaceae),a medicinal plant in China.The authors assessed the genetic diversity within and among populations of this species using inter-simple sequence repeat(ISSR) marker technology.A total of 58 individuals from 9 wild populations were detected by eight ISSR primers.These primers generated a total of 47 bands.At species level,the percentage of polymorphic loci(PPL) was 61.70%,Nei's gene diversity(H) was 0.2234,Shannon's information index(I) was 0.3302.At population level,the estimates of PPL=37.35%,H=0.1530,I=0.2228.The coefficient of genetic differentiation(Gst) was 0.2997.Gene flow among populations was 1.1682.AMOVA analysis indicated that most of the genetic variation(84.07%) resided within populations,and that 15.93% of the variation resided among populations.Φst= 0.159.UPGMA cluster analysis showed that individuals from the same population most clustered together based on Nei's genetic distance.There was no statistical significance relativity between genetic distance and geographic distance(r= 0.40495,p= 0.9791).In view of the above,a moderate level of gene conservation measures are suggested,including in situ and ex situ strategies.