明党参的濒危机制及其保护对策的研究

Studies on the endangerment mechanism of and conservation strategies for Changium smyrnioides

本文对明党参的资源状况、种群生态、种子结构、植株结实率与环境的关系及传粉生物学等方面进行了研究。从种子形态及分子水平对明党参的遗传多样性和遗传结构进行了分析。研究结果表明 ,明党参种子后熟阶段与梅雨气候的不协调是导致种子萌发率低及更新种群少的主要原因之一 ;人类活动破坏了明党参的适宜生境和种群数量 ,使得种群间基因流减小 ,进而导致严重的遗传漂变及种群间的分化。

The resource, the population ecology, structure and characters of seeds, pollination biology and the relationship between plumpness of seeds and environment were investigated in the rare plant Changium smyrnioides. The genetic diversity and genetic structure of the species were analysed by morphological characters of seeds, starch gel electrophoresis and RAPD analysis. The studies revealed lack of coordination between the ripening of the seeds and the season of East China, which resulted in low ratio of seed germination and low rate of population renewal. As human activity has destroyed and disturbed suitable habitat for the species, the range of each population has decreased and the habitat has become fragmented which has decreased gene flow between populations (Nm<1.0). The low gene flow suggests that genetic drift may play a prominent role in shaping the present-day genetic composition. Based on these results, some management strategies are proposed for protecting this species effectively.