不同喀斯特小生境中小蓬竹的遗传多样性

通过RAPD标记法对5类喀斯特小生境中小蓬竹的遗传结构及其多样性进行了分析。RAPD随机引物8个扩增共得87个清晰度高且重复性好的条带,分子量200～3 000 bp,含多态68条,物种PPL=78.16%,Nei’s基因多度H=0.291 3,Shannon多样性指数I=0.431 0。土面(TM)生长的小蓬竹遗传多样性水平最高(PPL=47.13%,H=0.195 3,I=0.283 4),石缝(SF)中的小蓬竹遗传多样性水平最低(PPL=39.08%,H=0.147 4,I=0.219 2)。POPGENE 32分析5类小生境中小蓬竹的遗传分化系数G_st=0.415 1,基因流N_m=0.704 5。5类小生境的小蓬竹间遗传相似系数(I)变化范围0.777 3～0.999 4,平均为0.865 6;遗传距离(D)变化范围0.000 6～0.251 9,平均为0.148 3。各类小生境的遗传多样性水平PPL均值为43.91%,5类小生境间的遗传分化G_st=0.405 4。研究结果说明,小生境间的差异增加了小蓬竹的遗传多样性。

Genetic Diversity of Ampelocalamus luodianensis in Different Microhabitats

By random amplified polymorphic DNA(RAPD) markers analysis, 5 kinds of karst microhabitats of Ampelocalamus luodianensis was conducted to study genetic diversity and genetic structure. Through 8 RAPD primers, 87 discernible DNA fragments in all weighted from 200-3 000 bp were cloned, and 68 in those were polymorphic loci, with percentage of polymorphic loci at the species level, PPL=78.16%, Nei's index H=0.291 3, and Shannon's Information Index I=0.431 0. The A.luodianensis grew on soil surface(TM) possessed the highest level of genetic diversity(PPL=47.13%, H=0.195 3 and I=0.283 4), while the A.luodianensis in stone crevice exhibited the lowest levels of genetic diversity(PPL=39.08%, H=0.147 4 and I=0.219 2). Coefficient of genetic differentiation (G_st) was 0.415 1(from the POPGENE32), and the gene flows(N_m) was 0.704 5. Among the 5 microhabitats, genetic identity varied from 0.777 3-0.999 4, genetic distance was different from 0.000 6-0.251 9, and the mean of them were 0.865 6-0.148 3 severally. Genetic diversity in niches at mean value was with PPL of 43.91%. Coefficient of genetic variation in niches was with G_st of 0.4054. The results indicated that differences of microhabitats increased the genetic diversity of A.luodianensis.