不同天然居群小蓬竹的遗传多样性

从分子水平探讨不同居群小蓬竹的遗传多样性以及与环境因子的相关性,揭示其濒危原因,为小蓬竹的保护和后续开发利用提供理论支撑,助力实施极危物种最佳保护策略。运用RAPD标记技术和POPGENE32对16个小蓬竹天然居群进行遗传多样性研究和遗传变异分析。结果表明,8个RAPD随机引物共扩增出105条清晰、重复性高的条带,其中多态性条带有98条,分子量300~2000bp;物种水平多态性位点百分率PPL=93.33%,有效等位基因数Ne=1.4942,Nei’s基因多样性H=0.3005,Shannon多样性指数I=0.4586;落湾(ZY1)居群的遗传多样性水平最高(PPL=60.95%,H=0.2329,I=0.3451),JP3]桃坡(PT1)居群的最低(PPL=44.76%,H=0.1700,JP]I=0.2523);16个天然居群的遗传分化系数Gst=0.3231,基因流Nm=1.0478,基于Shannon’s多样性指数的分化系数(HSP-HPOP)/HSP]为0.3429。小蓬竹居群内存在丰富的遗传多样性,各个天然居群间具有一定的遗传分化但分化水平并不高,主要的遗传变异存在于居群内部。

Genetic Diversity of Critically Endangered Plants Petrocalamus luodianensis from Different Natural Populations

To reveal the endangered reasons of Petrocalamus luodianensis, and provide theoretical support for the protection and utilization of this species, and then form the best protecting strategy for the critically endangered species, we explored the genetic diversity of different natural populations of P.luodianensis and the correlation with environmental factors at the molecular level. The genetic diversity and heritable variation of sixteen natural populations were studied by POPGENE 32 and the technology marked by random amplified polymorphic DNA(RAPD). The results showed that 105 high reproducible, stable and discernible DNA fragments weight from 200-3 000 bp were generated from 8 RAPD primers and 98 polymorphic locis are included, and the PPL is 93.33%. At the species level, the effective number of alleles(N_e) is 1.494 2, the Nei's gene diversity(H) is 0.300 5, and the Shannon's information index(I) is 0.458 6. The Luowan(ZY1) population possessed the highest level of genetic diversity(PPL=60.95%, H=0.232 9 and I=0.345 1), while the Taopo(PT1) population showed the lowest level of genetic diversity(PPL=44.76%, H=0.170 0 and I=0.252 3). In the 16 natural populations, the coefficient of genetic differentiation(G_st) is 0.323 1, the gene flows(N_m) is 1.0478 and the(H_SP-H_POP)/H_SP based on Shannon's Information Index(I) is 0.342 9, a little higher than G_st. Therefore, there is a significant variation and abundant diversity of the P.luodianensis, the intra-population variation is greater than the inter-population, and the genetic variation exists mainly within the intra-population.