金沙江干热河谷车桑子生殖枝生物量分配的性别差异

Gender Differences in Biomass Allocation of Reproductive Twigs of Dodonaea viscosain the Dry-hot Valley of Jinsha River

以车桑子生殖枝为材料,通过野外调查、取样以及各器官生物量的测定,研究金沙江干热河谷地区车桑子不同性别植株生殖枝生物量分配特征。结果表明:(1)金沙江干热河谷地区车桑子种群雄∶雌性别比为0.11,极显著的偏离1∶1(P<0.001),种群偏雌性。(2)车桑子生殖枝的形态特征和生物量分配特征均具有显著的性别差异;雌性植株生殖枝花朵生物量和总生物量显著高于雄性和两性植株(P <0.05),而后两者之间无显著差异;生殖枝生殖分配具有显著的性别差异(P <0.05),但生殖枝叶生物量无性别差异。(3)生殖枝生物量大小与花朵生物量、营养生物量均呈极显著正相关关系(P <0.001)。营养生物量与花朵生物量之间为显著正相关关系(P <0.01),生殖分配与生殖枝大小无相关关系。研究认为,车桑子生殖枝营养生长与生殖生长不具有权衡关系,且生殖分配不具有个体大小依赖性,特定生物量分配模式可能是对金沙江干热河谷区资源利用、环境适应的一种特殊形态模式。

Based on field investigation,sample collection and determination of biomass in various organs,we studied the biomass distribution characteristics of reproductive twigs of Dodonaea viscosain the dry-hot valley of Jinsha River.The results showed that：（1）female plants in D.viscosapopulation in the dry-hot valley of Jinsha River had significant advantages,and the sex ratio of male/female was 0.11,which showed a very significant deviation from the ratio of 1∶1（P〈0.001）.（2）The morphological characteristics and biomass allocation traits of the twigs were gender-different.The flower biomass and total biomass of female reproductive twigs were significantly higher than those of male and bisexual twigs（P〈0.05）,but there was no significant difference for biomass distribution between male and bisexual.Gender differences have been found in reproductive distribution,but not in leaves biomass of reproductive twigs.（3）There was a significant positive correlation between reproductive biomass of twigs and flower biomass,as well as vegetative biomass and flower biomass（P〈0.001）,but there was no significant correlation be-tween reproductive allocation and the size of reproductive twigs.Our results indicated that there was no trade-off between vegetative growth and reproductive growth,and reproductive allocation was not dependent on individual size.This biomass allocation model of D.viscosa might be an adaptation to the special environment of the dry-hot valley of Jinsha River.