海拔对青藏高原东缘弯齿风毛菊繁殖特征的影响

研究了海拔对青藏高原东缘不同海拔12个居群弯齿风毛菊繁殖特征的影响.结果表明: 弯齿风毛菊的个体大小、繁殖器官和营养器官生物量、每株头状花序数量及种子总数量均随海拔的升高而减小,而每个头状花序质量和种子百粒重随海拔的升高而增加,表明弯齿风毛菊可以通过减小个体大小来降低资源消耗,把获取的有限资源分配到繁殖部分以达到繁殖成功.为了保证顺利完成有性繁殖,繁殖分配随海拔升高而增大.弯齿风毛菊头状花序的数量与大小、种子数量与百粒重之间均存在资源分配上的权衡,以此来适应环境胁迫,提高自身的适合度.

Effects of altitude on the reproductive characteristics of Saussurea przewalskii at the eastern margin of the Tibetan Plateau,China.

The paper studied the effects of altitude on reproductive characteristics in 12 populations of Saussurea przewalskii at the eastern Qinhai-Tibetan Plateau, China. The results showed that the size, reproductive organ biomass, vegetative organ biomass, capitulum number, and seed number of individual plant decreased with the increasing altitude, and the capitulum mass and hundred-grain mass increased continuously. S. przewalskii could ensure its reproduction by reducing plant body size to decrease resource consumption, and increasing the allocation of limit resources to flower biomass. In order to ensure sexual reproduction, the reproductive allocation of the plants increased with increasing the altitude. There was a trade-off between capitulum number and capitulum mass, and between seed number and hundred-grain mass, which allowed the plants to maximize their fitness under stressful conditions.