海拔对青藏高原东部毛茛科植物繁殖特征和资源分配的影响

通过野外采样对青藏高原东部高寒草甸上两个海拔间3种常见毛茛科植物条裂银莲花(Anemone trullifo-liavar.linearis)、粗距翠雀花(Delphinium pachycentrumHemsl.)和钝裂银莲花(Anemone obtusiloba)的繁殖性状和资源分配进行了研究,并对植物在极端环境下采取的繁殖策略及繁殖模式进行了探讨.结果显示:(1)3个物种的株高都随着海拔的升高而降低;同一物种的花大小在不同海拔间均无显著差异;条裂银莲花单个种子重随海拔的升高而增加,但虫食数/株、结籽率和种子数/株均随着海拔的升高而减少;钝裂银莲花的繁殖分配、虫食数/株、种子数/株和单个种子重均随着海拔的升高而减小.(2)不同海拔条裂银莲花的个体大小与单花重、雄蕊重、虫食数/株均呈显著正相关,且回归斜率在海拔间有显著差异.粗距翠雀花花期的雄蕊重与个体大小呈显著正相关,但这种异速关系不受海拔和个体大小的影响;钝裂银莲花的个体大小与花期的所有繁殖特征以及果期的种子重/果实均呈显著正相关,不同海拔间个体大小与种子重/果实的斜率差异显著,且与花期各繁殖性状异速关系的截距差异显著.研究表明海拔对植物的个体大小以及种群间的繁殖对策和繁殖成功率有着重要的影响.

Influence of Altitude on Reproductive Traits and Resource Allocation of Species of Ranunculaceae at East Qinghai Tibetan Plateu

The present study examined the variations of traits and resource allocation of three species of Ranunculaceae between different altitudes at the eastern Qinghai Tibetan Plateau.The results showed:(1) decreased plant height rather than flower size at higher altitude for three species(A.trullifolia,D.pachycentrum and A.obtusiloba);larger seed size,but decreased aborted seeds per plant,seed set and seed number per plant in higher altitude population of A.trullifolia;significant decrease of all traits and resource allocation in A.obtusiloba with the altitude increasing.(2)The plant size of A.trullifolia was positively correlated with single flower mass,androecium mass and aborted seeds per plant,with significantly differed slopes between different altitudes.For D.pachycentrum,the plant size was significantly positively correlated with androecium mass,regardless of effects of altitude and plant size.For A.obtusiloba,the plant size was significantly positively correlated with all reproductive characters,and the regression slope between plant size and seed mass per fruit differed between different altitudes.The results suggested there is an important effect of altitude on plant size,reproductive strategies and reproductive success within populations.