Lvarez-Cansino Leonor, Barradas Mari Cruz D Az, Zunzunegui Mar A, Esquivias Mari Paz, Dawson Todd E
University of Wisconsin-Milwaukee, Department of Biological Sciences, PO Box 413, Milwaukee, WI 53201, USA.
Universidad de Sevilla, Departamento de Biología Vegetal y Ecología. Aptdo. 1095 41080. Sevilla, Spain.
Funct Plant Biol. 2012 Dec;39(12):968-978. doi: 10.1071/FP12131.
Different requirements for reproduction between sexes in dioecious plants can lead to gender-specific physiological responses to environmental constraints. Females generally endure higher reproductive investment and costs than males, displaying lower water and nutrient use efficiency and growth. We studied the ecophysiology of the dioecious shrub Corema album L. (D.) Don. to assess how drought impacts physiological responses and gender dimorphism along an aridity gradient within the species' range. Leaf gas exchange, photochemical efficiency (Fv/Fm), water potential (Ψ), vegetative growth (VG) and leaf C isotopic discrimination and nitrogen content were measured in three populations under markedly different climatic conditions. Physiological responses and growth indicated higher level of stress in the drier environments, leading to increased WUE (Δ) and lower VG. Physiological stress increases among plants were related to incremental changes in the degree of gender dimorphism, with significant effects on Ψ and Fv/Fm (P<0.05); males showed higher VG (P<0.001). Multivariate analysis of instantaneous and integrated measurements revealed gender-related effects across the climatic gradient (P<0.01). Reproduction investment has an effect on the physiological performance and growth of C. album. Gender responses are site-specific, being influenced by climate. The increase in physiological stress with aridity could lead to the potential retreat and variation in structure in these populations if genders are affected differently by the predicted climate change.
雌雄异株植物两性之间不同的繁殖需求会导致对环境限制产生特定性别的生理反应。通常情况下，雌性比雄性承受更高的繁殖投入和成本，表现出更低的水分和养分利用效率以及生长速度。我们研究了雌雄异株灌木白滨藜（Corema album L. (D.) Don.）的生态生理学，以评估干旱如何影响该物种分布范围内沿干旱梯度的生理反应和性别二态性。在三种气候条件显著不同的种群中，测量了叶片气体交换、光化学效率（Fv/Fm）、水势（Ψ）、营养生长（VG）以及叶片碳同位素判别和氮含量。生理反应和生长表明，在更干旱的环境中胁迫水平更高，导致水分利用效率（Δ）增加，营养生长降低。植物间生理胁迫的增加与性别二态性程度的递增变化相关，对Ψ和Fv/Fm有显著影响（P<0.05）；雄性表现出更高的营养生长（P<0.001）。对瞬时和综合测量结果的多变量分析揭示了整个气候梯度上与性别相关的影响（P<0.01）。繁殖投入对白滨藜的生理表现和生长有影响。性别反应具有地点特异性，受气候影响。如果不同性别受预测气候变化的影响不同，随着干旱加剧生理胁迫增加可能会导致这些种群潜在的退缩和结构变化。
