Correlation analysis between altitude and reproductive allocation and floral traits in Saussurea iodostegia Hance | 紫苞雪莲花期繁殖分配及花部特征与海拔高度的相关分析

chinois. 对不同海拔高度下的菊科风毛菊属植物紫苞雪莲（Saussurea iodostegia Hance）10个居群的花期繁殖器官特征和繁殖分配进行研究，为探讨紫苞雪莲如何与胁迫环境相适应及提高其繁殖分配率提供科学依据。2009-09，在位于青藏高原东缘的甘肃甘南藏族自治州，于不同海拔下（3 050，3 200，3 300，3 400，3 500，3 600，3 700，3 800，3 925，4 000 m）采集10个居群的紫苞雪莲，每个居群取20株样品，测定紫苞雪莲的性器官长度、花粉数、个体大小及繁殖分配，并分析各个指标与海拔高度间的相关性。紫苞雪莲个体大小与海拔高度呈极显著负相关（P0.01），紫苞雪莲繁殖分配与海拔高度呈极显著正相关（P0.01），个体大小与繁殖分配呈极显著负相关（P0.01），花药和花丝长度及花粉数与海拔高度呈极显著负相关（P0.01），花柱长度与海拔高度呈极显著正相关（P0.01），花丝长度与花粉数呈显著正相关（P0.05），花柱长度与花粉数呈显著负相关（P0.05）。海拔高度对紫苞雪莲的个体大小及繁殖分配有重要影响，随着海拔升高，植株可获取的资源总量降低，分配给繁殖器官的相对资源量增加，并且在花粉数随着海拔的升高而减少的情况下，紫苞雪莲通过花柱长度的增加来提高柱头对传粉昆虫的感受性，从而在一定程度上提高了其繁殖成功率。

anglais. The correlation between ten populations traits of sexual organs and reproductive allocation of Saussurea iodostegia Hance in different altitudes was studied to provide a basis for the research how Saussurea iodostegia Hance adapted to the stressful environment and raised its reproductive success ratio. In Ganan Autonomy State of Gansu province in the eastern Qinghai Tibetan Plateau, ten populations of Saussurea iodostegia Hance in different altitudes (3 050, 3 200, 3 300,3 400, 3 500,3 600, 3 700, 3 800, 3 925, 4 000 m) were collected in September 2009, length of sexual organs, pollen number, individual size and reproductive allocation were measured, analysis of correlation between them and altitude was conducted. The results showed: There was a significantly negative correlation between individual size and altitude (P0.01), a significantly positive correlation between reproductive allocation and altitude (P0.01), a significantly negative correlation between individual size and reproductive allocation (P0.01), significantly negative correlations among anther length, filament length, pollen number and altitude (P0.01) and a significantly positive correlation between style length and altitude (P0.01), a positive correlation between filament length and pollen number (P0.05), and a negative correlation between style length and pollen number (P0.05). The results suggested there was an important effect of altitude on plant size and reproductive strategies within populations. With increasing altitude, total acquired resources decreased and relative resources allocating reproductive organs increased, the pollen number decreased and the style length elongated. Saussurea iodostegia Hance enhanced the sensitivity to pollinators, and increased rate of success of reproduction.