Intra- and inter-sexual competition of Populus cathayana under different watering regimes
Intra- and inter-sexual competition of Populus cathayana under different watering regimes
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不同浇水方式下青杨的性内和性间竞争
DOI：
10.1111/1365-2435.12180
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发表时间：
2014-02-01
影响因子：
5.2
通讯作者：
Li, Chunyang
中科院分区：
文献类型：
--
作者：
Chen, Juan;Duan, Baoli;Li, Chunyang
1研究表明，白杨对环境胁迫的反应具有性别二型性，并在蛋白质组成、基因转录以及形态和生理过程上存在性别差异。然而，白杨的性竞争尚未得到研究。以青杨雌雄株为模型，研究了干旱胁迫和水分充足条件下青杨雌雄株间的性内竞争和性间竞争。结果表明，在不同水分条件下，竞争对青杨的性二型性有显著影响。性竞争是环境依赖性和干旱的修改。在雌性中，干旱加剧了性内竞争的负面影响。在干旱胁迫下，雌性动物类似的资源利用模式可能会加剧对资源的压力。在性间竞争中，在水分充足的条件下，雌性比雄性表现出更强的竞争能力，而在干旱胁迫下，雄性表现出轻微的竞争优势。与性内竞争相比，性间竞争似乎缓解了青杨对干旱胁迫的性二型性反应，雌性增加了适合度，而雄性降低了适合度。资源利用模式的两性异形和生态位隔离可能有助于在特定环境中的性竞争。性竞争影响了青杨种群的竞争能力和适合度，可能导致青杨种群的性别空间分离。
1Previous studies have demonstrated that poplar is sexually dimorphic in its responses to environmental stresses and provided evidence of sex-related differences in protein composition, gene transcription and morphological and physiological processes. However, sexual competition of poplar has not yet been studied. We employed Populus cathayana males and females as a model to investigate intra- and intersexual competition under well-watered condition and drought stress. Our results indicated that competition significantly affected sexual dimorphism of P.cathayana under different watering regimes. Sexual competition was environment-dependent and modified by drought. In females, drought intensified the negative effect of intrasexual competition. Similar resource utilization patterns of females may aggravate pressure for resources under drought stress. Under intersexual competition, females showed a greater competitive ability than males under well-watered condition, while males showed a slight competitive advantage under drought stress. Intersexual competition seems to alleviate the sexual dimorphism of P.cathayana in response to drought stress, as females increase fitness and males decrease fitness compared with intrasexual competition. Sexual dimorphism in resource utilization patterns and niche segregation may contribute to sexual competition in a given environment. Sexual competition was found to affect competitive ability and fitness of both sexes, which may cause spatial segregation of sexes in P.cathyana populations.