淫羊藿无性系种群构件生物量分配格局

摘要

淫羊藿为具有克隆生长习性的多年生根茎型草本植物,是重要的药用资源植物.该文以野生淫羊藿为研究材料,于营养生长期和有性生殖期对无性系分株种群进行取样,比较分析不同时期、不同构件生物量分配格局.结果表明,营养期与有性生殖期无性系分株种群生物量差异不显著,但各构件生物量百分比差异显著.营养期根生物量比(RMR)、支持结构生物量比(SBR)和根冠比(R/C)均大于有性生殖期;而叶生物量比(LMR)和叶重分数(LMF)小于有性生殖期.在有性生殖期,营养分株(VR)生物量(83.93%)远远大于生殖分株(RR)生物量(16.07%),用于生殖器官(花)的生物量投资比例非常小(1.45%),叶构件生物量分配比例(50.68%)最大,地下根茎(32.03%)和支持结构(15.84%)生物量分配比例次之.高比例的叶构件生物量有利于合成大量有机物质,这些物质储存于地下根茎中以维持基株在资源缺乏季节的生长,保证种群的生存和繁衍.这些都暗示着淫羊藿不仅有很强的克隆生长能力,而且采取克隆生长为主,有性繁殖为辅的手段维持种群的繁衍与扩散.%Epimedium. brevicornum has many pharmacological activities proved by clinical application,thus it is a vital species of medicinal plant. It is an herbaceous plant with perennial rhizome and a eurytopic plant in Sichuan, China. The ramet populations of E. brevicornum at vegetative phase (VP) and reproductive phase (RP) have been sampled to study the patterns and dynamics of biomass allocation in the different module populations. The results show that the difference of ramet population biomass between VP and RP is not significant. However, the ratios of biomass allocated to different modules are significantly different. The RMR, SBR and R/C at VP are more than at RP, the LMR and LMF at VP are less than at RP on the contrary. Concerning the reproductive phase, the ratio of biomass allocated to vegetative ramet (VR) (83.93%) is more than that to reproductive ramet(RR) (16.07%). As a crucial organ of sexual reproduction, flower accounts for only 1.45% of the total mass in ramet population and approximately 10.44% in reproductive ramet. The proportions of biomass allocated to different modules decreased in the following order: LMR (50.68%), RMR (32.03%), SBR ( 15.84% ) and FR ( 1.45% ). The larger value of LMR can be helpful for producing of dry matters (such as carbohydrate) by physiological process in leaf organ. The dry matters stored in rhizome are crucial at the vegetative phase.Such a function of rhizome is very useful for plant to overcome the difficulty in growth due to temporal heterogeneity of the environmental resources and ensure the survivability and propagation of ramet population. The results imply that there are strong ability and integration of clonal growth of E. brevicornum, the asexual propagation of clonal growth is the main means of reproduction, and the sexual reproduction plays a secondary role in formation and dispersion of ramet population.