苦草(Vallisneria natans)无性系结构与生长特征对种群密度的响应  

Responses of Clone Structure and Growth Characteristics of Vallisneria natans to Population Density

作　　者：朱协军 韩璐 方根生 

机构地区：[1]上海园林绿化建设有限公司,上海200333 [2]上海市崇明水生水环境研究所,上海202161 [3]上海水源地建设发展有限公司,上海200092

出　　处：《基因组学与应用生物学》2017年第7期3003-3007,共5页Genomics and Applied Biology

基　　金：上海建工集团股份有限公司重点科研项目课题(14JCSF-25);崇明科委项目(CKS2015-03)共同资助

摘　　要：本研究对不同种群密度下苦草(Vallisneria natans)的无性系结构和生长特征进行了野外原位研究。研究表明,苦草生物量、匍匐茎长度、匍匐茎数、单株叶片数和单株生物量均与密度呈显著线性正相关,匍匐茎平均长度与密度呈显著线性负相关。苦草无性系种群个体生物量变化范围为0.01~0.95 g,在不同密度下,生物量结构均以小型个体为主,但随着密度增加,种群中小个体和大个体的比例减少,中等大小个体比例增加,个体大小不等性降低。苦草匍匐茎长度变化范围为1.7~11.2 cm,各密度下均以中等长度为主,随着密度增加,匍匐茎长度表现出缩短的趋势。研究认为,苦草在高密度条件下,通过缩短匍匐茎长度降低邻株竞争强度;在低密度条件下,则通过增加匍匐茎长度,实现种群的迅速扩展,由此体现出苦草无性系种群在不同密度下的生态适应对策。This study analyzed the clone structure and growth characteristics of Vallisneria ncttans under different population densities based on an in-situ research. As a result, the biomass, stolon length, stolon number, leaf num- ber and biomass per plant of Vallisneria natans all showed a significant positively linear correlation with popula- tion density, and the average stolon length showed a significant negatively linear correlation with population densi- ty. The individual biomass range of Vallisneria natans was 0.01-0.95 g. Under different densities, the biomass structure was mainly comprised of minor size individuals. With the increment of density, the proportion of minor and large size individuals was decreased. However, the proportion of middle size individuals was decreased. Thus, the inequality of individual sizes became lower. The stolon length range of Vallisneria natans was from 1.7 cm to 11.2 cm, and they were mainly comprised of middle length stolons under different densities. The stolon length dis- played a decreasing tendency whenthere was the increase in density. We concluded that the Vallisneria natans de- creased the interspecific competition intensity by shortening its stolon length under high density, and enhanced the population expansion by increasing the stolon length under low density, which reflected the ecological adaptionstrategies of its clone population under different density.

关 键 词：沉水植物 密度制约 大小不等性 种群调节 生理整合 

分 类 号：Q948[生物学—植物学]