Sexual differences in growth and defence of Populus yunnanensis under drought stress
Sexual differences in growth and defence of Populus yunnanensis under drought stress
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DOI：
10.1139/cjfr-2018-0270
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发表时间：
2019-01
影响因子：
2.2
通讯作者：
Rong Zhang;Junyan Liu;Qinsong Liu;H. He;Xiao Xu;T. Dong
中科院分区：
文献类型：
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作者：
Rong Zhang;Junyan Liu;Qinsong Liu;H. He;Xiao Xu;T. Dong
在干旱栖息地下，雌雄异体的木本物种通常表现出雄性偏向的性别比例，这可能导致干燥土壤的脆弱性。然而，性别比例偏差是否与干旱胁迫条件下生长和防御昆虫食草的性别特异性反应有关尚不清楚。我们研究了云南杨对两种水处理（40% 和 100% 田间持水量）的生长和防御方面的性反应。干旱胁迫降低了雌性和雌性植物的生长（例如，高度增量、气体交换、光合氮利用效率和水势），并降低了雌性而非雄性的叶片含水量和防御性能（咀嚼叶片受损面积增加，叶片总酚、缩合单宁和黄酮类化合物含量降低）。此外，在干旱条件下，雌性的防御性能低于雄性。此外，在所有叶子落叶处理的干旱胁迫期间，两性的植物死亡率均增加，并且雌性植物的死亡率高于雄性植物。我们的研究结果表明，云南松在生长和防御干旱方面的性反应显着不同，并且雌性云南松的防御能力低于雄性，这可能解释了自然种群中存在的雄性偏重的性别比例。因此，这项研究为预测干燥生境中雌雄异体植物物种的种群动态提供了新的见解。
Dioecious woody species often exhibit male-biased sex ratios under drought habitat, which may result in vulnerability in drying soils. However, whether biased sex ratios are associated with sex-specific responses in growth and defence against insect herbivory under drought stress conditions is unknown. We investigated the sexual responses in terms of growth and defence in Populus yunnanensis Dode in response to two water treatments (40% and 100% field capacity). Drought stress reduced the plant growth (e.g., height increment, gas exchange, photosynthetic nitrogen use efficiency, and water potential) of both sexes and reduced the leaf water content and defensive performance (increased damaged area by leaf-chewing generalists and decreased leaf contents of total phenolics, condensed tannins, and flavonoids) of the females but not the males. Moreover, female defensive performance was lower than that of the males under drought conditions. Additionally, the plant mortality rate increased for both sexes, and it was higher for females than for males during drought stress in response to all leaf defoliation treatments. Our results suggest that sexual responses in terms of growth and defence to drought are significantly different and that P. yunnanensis females have a lower defence capability than males, which may explain the male-biased sex ratio that exists in the natural population. Hence, this study provides new insight into forecasting population dynamics for dioecious plant species in drying habitats.