【作者】 周铜水； 郭宏波； 吴千红；

【Author】 Zhou Tong-Shui~*,Guo Hong-Bo,Wu Qian-Hong School of Life Sciences,Fudan University,Shanghai,200433

【机构】 复旦大学生命科学学院；

【摘要】 从党参(Codonopsis pilosula(Franch.)Nannf.)的主要分布区山西、陕西和甘肃三省采集8个野生居群和8个栽培居群共463个样本,另在主产区甘肃陇西县两次取样,分别采集7个居群138个样本和5个居群150个样本。采用ISSR和RAPD分子标记技术,对野生及栽培党参居群的遗传多样性、遗传结构及其地理分布格局进行深入分析和比较研究,得出如下结论:1.党参野生与栽培居群均具有较高遗传多样性。党参野生居群具有较高遗传多样性(Pp=96.18%,h=0.288,I=0.442),居群内遗传变异为73.2%;党参栽培居群也具有较高遗传多样性(Pp=96.18%,h=0.266,I=0.414),与野生居群明显不同的是栽培居群82%的遗传变异存在于居群内个体间。在物种水平上,党参多态位点可分率Pp高达97.0%,Nei氏基因多样性h=0.285,香农指数I=0.440,遗传变异主要存在于居群内个体间(76.7%)。说明党参遗传多样性总体仍处于较高水平,其遗传结构体现出广布种、多年生和异交物种的特性。2.过度利用导致山西长治地区"潞党参"野生居群遗传多样性显著下降。结果表明,山西长治野生居群遗传多样性(h=0.2090,I=0.3272)显著低于其它野生居群,接近同科濒危物种裂叶泡沙参以及不同科濒危物种多样性水平。导致这一后果的直接原因是由于山西长治是"上党人参"或"潞党参"的原产地,历史上曾发生过大规模过度利用事件。这种毁灭性破坏使得山西长治"潞党参"野生种群数量锐减,居群大幅变小,从而形成了严重遗传瓶颈。3.人工栽培有效保存了党参的遗传多样性。尽管栽培居群遗传多样性普遍低于野生居群,但山西长治地区栽培居群遗传多样性显著高于同产地野生居群(h=0.2674,I=0.4152 vs.h=0.2090,I=0.3272),说明人工栽培是保存党参遗传多样性的有效方式。研究认为目前这种粗放的农家栽培模式,以及地理隔离和异质化生境下的自然分化,可能是栽培党参保持较高遗传多样性的主要机制。4.党参种质资源的取样策略,既要有足够的居群数和样本量,也要考虑居群及样本的地理分布和采样范围,提出了党参种质资源原位保护和迁地保护的具体实施规划。本文首次以广布种大宗药材党参原植物为研究对象,全面系统地研究和分析了药用植物资源利用和保护中的共性问题,揭示了过度利用会造成野生药用植物严重遗传瓶颈,使居群遗传多样性大幅下降;现行粗放药用植物栽培能够有效地保持居群遗传多样性。这些研究结果对于药用植物遗传资源的保存和保护具有重要意义,同时对于其它植物的保护生物学研究也具有重要参考和借鉴价值。更多还原

【Abstract】 A total of 463 samples from eight wild and eight cultivated populations were collected from Shaanxi,Shanxi and Gansu provinces.In addition,138 samples from 7 populations and another 150 individuals from 5 populations were separately collected in different times from Longxi county of Gansu province.Both inter-simple sequence repeat(ISSR) marker and randomly amplified polymorphic DNA(RAPD) marker were employed to estimate their genetic diversity,genetic structure and spatial distribution of the diversity.The research contents and conclusions were listed as follows: 1.Both the wild and the cultivated populations of C.pilosula maintain a relatively high level of genetic diversity.The wild populations were found to have a relatively high genetic diversity with Pp=96.18%,h=0.288,and I=0.442,and the major genetic variation was found within population(73.21%).The cultivated populations also displayed a relatively high level of genetic diversity(Pp=96.18%,h=0.266,I=0.414),but more genetic variation existed within populations(82%). At species level,C.pilosula exhibited a relatively high genetic diversity with Pp=97.0%,h=0.285 and I=0.440,and the major genetic variation resided within population(76.70%).The genetic diversity level and genetic structure of C.pilosula were consistent with the general patterns of wide-spread,perennial and outcrossing species. 2.The genetic diversity of wild populations of"Lu Dangshen"from Changzhi county of Shanxi province is obviously decreased due to over-harvest in the history.The result showed that the genetic diversity of wild populations of"Lu Dangshen"from Changzhi was significantly lower than that of other wild populations concluded in this study.Its value(h =0.2090,I=0.3272) was nearly equal to that of Adennophora lobophylla,an endangered species of the same family,and that of other endangered plants of relative families.The current genetic diversity pattern of wild populations in this area might be attributed to the severe over-harvesting practice recorded in the history.The over-harvest in the past had resulted in a severe decrease of the species individuals and population size.For this reason,a great genetic bottleneck was formed,and as a consequence,restrained the genetic diversity of this species. 3.The present irregular and sparse cultivation practices of C.pilosula were proved to be an efficient way to maintain genetic diversity of this species.Although the genetic diversity of the cultivated populations was generally lower than that of wild populations,but the cultivated populations in Changzhi of Shanxi province showed much higher level than that of wild populations in the same area.This finding suggested that the current cultivation practices,i.e.,random collecting,preserving, and planting seeds of C.pilosula,and the spatial isolation and heterogenous habitat of populations,might be the main reasons for the efficient conservation of genetic diversity of the studied species. 4.An effective sampling strategy for conservation of C.pilosula should consider not only the population number and the population size,but also the sampling range of individuals and the spatial distribution of populations.More detailed implementary schemes for in situ and ex situ germplasm conservation of C.pilosula were proposed. This study explored comprehensively for the first time the common questions encountered in the resources development, germplasm conservation and sustainable utilization of medicinal plants by employing C.pilosula,a wild-spread species,as a research model.Our results showed that over-harvest of the wild resources would result in a severe genetic bottleneck and consequently decrease significantly the genetic diversity of wild populations.However,the present irregular and sparse cultivation practices,i.e.,random collecting,preserving,and planting seeds without deliberate selection,might be an effective way to conserve genetic resources of medicinal plants.These findings are of significant theoretical and practical values for protection and conservation of genetic resources of medicinal plant as well as other species.更多还原