芍药野生与栽培群体的遗传变异研究

目的探讨芍药(Paeonia lactiflora Pall.)的野生群体和栽培群体之间的遗传分化与中药材赤芍和白芍道地性形成的关系。方法应用RAPD技术,使用21条随机引物对来自11个产地的43株有代表性的芍药样品进行PCR扩增。结果(1)芍药在物种水平上的多态位点比率为85.26%,基因多样度为0.166;其中野生群体(77.61%)高于药用栽培群体(54.96%)及观赏栽培群体(61.76%);(2)芍药群体间的遗传变异占总变异的29.50%,基因分化系数为0.254;野生与药用群体之间遗传距离最远(0.3632),药用与观赏群体之间遗传距离最近(0.0973),群体间遗传分化显著(P<0.001);(3)从聚类图看,芍药种内大致分为野生与栽培两大类群。在野生群体中来自多伦的芍药单独聚为一类;在药用栽培群体中产于安徽亳州的与产于浙江磐安、缙云的芍药各聚为一类。结论首次揭示了芍药种群的遗传分化,在分子水平上为赤芍和白芍道地性的形成找到依据。鉴于多伦产芍药(赤芍道地药材的主要来源)的种质资源面临灭绝的危险,建议列为濒危种质加以保护。

A STUDY ON GENETIC VARIATION BETWEEN WILD AND CULTIVATED POPULATIONS OF PAEONIA LACTIFLORA PALL

AIM: To discuss the genetic differentiation between wild and cultivated populations of Paeonia lactiflora Pall., and to find the reason for forming the genuineness of Radix Paeoniae rubra (Chishao) and Radix Paeoniae alba (Baishao). METHODS: Forty three representative samples of P. lactiflora from 11 localities were analyzed by RAPD method with 21 random primers. According to RAPD results, the genetic diversity and genetic differentiation of P. lactiflora were detected by the percentage of polymorphic sites (PPB), the coefficient of gene differentiation (GST) and analysis of molecular variance (AMOVA). RESULTS: (1) At species level, the PPB of P. lactiflora was 85.26%, the Nei's gene diversity (Ht) was 0.166. The PPB in wild population (WP) was 77.61%, which was more than that (54.96%) in cultivated population for medicine (MP), and that (61.76%) in cultivated population for ornament (OP). (2) AMOVA showed that 29.50% of the genetic diversity resulted from differentiation among populations. Pairwise Phist distance (0.3632) between WP and MP was furthest, while that (0.0973) between MP and OP was closest, indicating population differentiation was significant (P < 0.001). (3) In general, cluster analysis revealed that the samples of P. lactiflora were divided in wild and cultivated groups (except for 39). In WP, individuals of Duolun were separated from those of other localities. In MP, the clusters of samples corresponded well with their own habitats. CONCLUSION: In addition to environmental factor, genetic differentiation should be the main cause for the genuineness of "Chishao" and "Baishao". Because of over collection and worse habitat, P. lactiflora in Duolun, whose root is the famous Chinese Geo-herbal--"Duolun Chishao", is progresively rare. So, it should become the endangered germplasm resource to protect.