Bakhtiari Moe, Formenti Ludovico, Caggìa Veronica, Glauser Gaëtan, Rasmann Sergio
Institute of Biology University of Neuchâtel Neuchâtel Switzerland.
Institute of Plant Science University of Bern Bern Switzerland.
Ecol Evol. 2019 Feb 27;9(7):3740-3755. doi: 10.1002/ece3.4999. eCollection 2019 Apr.
Along ecological gradients, phenotypic differentiation can arise through natural selection on trait diversity and magnitude, and environment-driven plastic changes. The magnitude of ecotypic differentiation versus phenotypic plasticity can vary depending on the traits under study. Using reciprocal transplant-common gardens along steep elevation gradients, we evaluated patterns of ecotypic differentiation and phenotypic plasticity of several growth and defense-related traits for two coexisting but unrelated plant species, and . For both species, we observed ecotypic differentiation accompanied by plasticity in growth-related traits. Plants grew faster and produced more biomass when placed at low elevation. In contrast, we observed fixed ecotypic differentiation for defense and resistance traits. Generally, low-elevation ecotypes produced higher chemical defenses regardless of the growing elevation. Yet, some plasticity was observed for specific compounds, such as indole glucosinolates. The results of this study may suggest that ecotypic differentiation in defense traits is maintained by costs of chemical defense production, while plasticity in growth traits is regulated by temperature-driven growth response maximization.
沿着生态梯度，表型分化可通过对性状多样性和幅度的自然选择以及环境驱动的可塑性变化而产生。生态型分化与表型可塑性的程度可能因所研究的性状而异。利用沿着陡峭海拔梯度设置的 reciprocal transplant-common gardens，我们评估了两种共存但不相关的植物物种（ 和 ）几种与生长和防御相关性状的生态型分化模式和表型可塑性。对于这两个物种，我们观察到生态型分化伴随着与生长相关性状的可塑性。当置于低海拔时，植物生长更快且产生更多生物量。相比之下，我们观察到防御和抗性性状存在固定的生态型分化。一般来说，低海拔生态型产生更高的化学防御，无论生长海拔如何。然而，对于特定化合物，如吲哚硫代葡萄糖苷，观察到了一些可塑性。本研究结果可能表明，防御性状的生态型分化通过化学防御产生的成本得以维持，而生长性状的可塑性则由温度驱动的生长反应最大化来调节。
