林生风毛菊(Saussurea sylvatica)头状花序权衡机制的海拔差异  

The trade-off mechanism of capitulum in Saussurea sylvatica along an elevation gradient

作　　者：王一峰[1] 祁如林 杨亚军[1] 杨洋[1] 毛婉嫕 WANG Yi-feng;QI Ru-lin;YANG Ya-jun;YANG Yang;MAO Wan-yi(College of Life Science,Northwest Normal University,Lanzhou 730070,Gansu,China)

机构地区：[1]西北师范大学生命科学学院,甘肃兰州730070

出　　处：《西北师范大学学报（自然科学版）》2018年第1期61-66,共6页Journal of Northwest Normal University(Natural Science)

基　　金：国家自然科学资助基金项目(31460105);国家中医药管理局项目(201207002)

摘　　要：以广泛分布于青藏高原相对高海拔区的林生风毛菊为研究对象,通过采样调查法和烘干称量法等实验生态学方法研究不同海拔居群间头状花序大小-数量的权衡关系.结果表明,随着海拔的升高,地上生物量、株高、繁殖和营养器官生物量以及每株头状花序数量均呈减小趋势(P<0.01),而繁殖分配(P=0.023)和每个头状花序质量(P=0.02)均呈增大趋势;随着每个头状花序质量的增加,每株头状花序的总数量呈现不断减小趋势.研究发现,高海拔的环境胁迫导致林生风毛菊个体减小,植株在头状花序大小和数量的资源分配上存在"此消彼长"的权衡,即通过增加单个头状花序质量、减小植物头状花序数量的资源分配策略来保证其种群的繁殖成功率,以补偿在高海拔区的恶劣环境对种群繁衍带来不利影响,反映了高山植物资源分配的可塑性以及自身繁殖适合度的提高.This article is to study the changes of the relationship between capitulum size and capitulum number in Saussurea sylvatica populations with elevation in the eastern Qinhai-Tibetan Plateau.We used the sample investigation method and dry mass method to evaluate morphological characteristics of S sylvatica at different elevations.With increasing elevation,the size(aboveground biomass and plant height),reproductive organ biomass,vegetative organ biomassand capitulum number of individual plants continuously decrease(P<0.01),while the reproductive allocation(P=0.023)and capitulum mass weight(P=0.02)are increasing continuously.With the capitulum mass weight increasing,all the capitulum number decrease continuously.Therefore,the stressful environment of high elevation lead to S sylvatica reducing plant body size,and there is a trade-off between the flower size and flower number.Consequently,a change in the reproductive strategy with a trade-off between capitulum size and capitulum number ensures successful reproduction of the S sylvatica populations in adverse environments,which allows the plants to maximize their fitness under stressful conditions.

关 键 词：林生风毛菊 头状花序 繁殖分配 权衡机制 海拔差异 

分 类 号：Q948.114[生物学—植物学]