川西风毛菊花期资源分配随海拔的变化

Changes in flowering resource allocation of Saussurea dzeurensis with elevations

以分布于青藏高原东缘的川西风毛菊(Saussurea dzeure)为试验材料,研究了其位于不同海拔高度的16个种群的花期资源分配。结果显示:1)花期植物个体大小、头状花序数量、繁殖器官及营养器官生物量、花瓣质量、雌蕊及雄蕊群质量均与海拔呈负相关关系,每个头状花序质量与海拔呈正相关关系;2)繁殖分配和雄性分配与海拔呈正相关关系,营养分配和雌性分配与海拔呈负相关关系;3)花期头状花序的数量和大小、繁殖分配和营养分配以及雄性分配和雌性分配之间均存在资源分配上的权衡。由此推论:1)海拔作为外界因子对川西风毛菊花期各生物量及资源分配有显著的影响;2)在资源有限的情况下,川西风毛菊权衡对各结构的资源投入,通过增加繁殖分配和雄性分配来适应胁迫环境,提高繁殖的成功率。

Aims Our objective is to study the effect of elevation on the reproductive allocation and sexual allocation of Saussurea dzeurensis during the flowering season. MethodsWe used the field investigation method and dry mass method to evaluate morphological characteristics ofS. dzeurensisatdifferent elevations. Important findingsElevation had a significant impact on the biomass and resource allocation ofS. dzeurensis; reproductive allocation and male allocation were positively correlated with elevation, but vegetative allocation and female allocation were negatively correlated with elevation; there was a trade-off of resource allocation be-tween capitulum number and mass, between reproductive allocation and vegetative allocation, and between male allocation and female allocation; When resources were limiting, the resource input of every structure ofS. dzeurensis was balanced by increasing reproductive allocation and sexual allocation so that the plant can adapt to the stressful environment and have high rate of reproductive success.