We investigated genecology and ecophysiological mechanisms of the polymorphism of leaf trichome density of Leptospermum recurvum Hook. f. (Myrtaceae) in the deglaciated summit zone above 3,000 m a.s.l. of Mt. Kinabalu, Borneo. Various phenotypes with variable foliar trichome densities occurred sympatrically in the same population, and the composition of coexisting phenotypes varied substantially among populations. We conducted a common garden experiment by sowing seeds from multiple maternal trees of different leaf trichome densities. We found a significant relation between pubescence of maternal trees and offspring, which indicated that leaf trichome density had a genetic basis. Microsatellite analysis revealed that there was no barrier to gene flows among phenotypes or among populations, and very low neutral genetic differentiation among populations with high gene flows for both directions of phenotypes. The soils in the sites dominated by pubescent trees were significantly more desiccated than in the sites dominated by glabrous trees during a short drought. Glabrous trees had a significantly greater mortality rate than pubescent trees after an intensive El Niño drought (13.7 vs. 3.9%) in the same sites where both phenotypes occurred sympatrically. Pubescent individuals demonstrated a significantly greater photosynthetic water‐use efficiency than glabrous individuals. El Niño droughts could cause large difference in soil moisture among sites and that a greater desiccation stress removed glabrous phenotypes as one end of divergent natural selection to form pubescent populations. These results implied that the process shaping the phenotypic polymorphisms involved strong gene flows combined with ongoing divergent selection.

中文翻译：

---

在婆罗洲山南亚巴鲁山热带亚高山带振荡的大气干燥条件下，维持稳定的豆蔻科（Myrtaceae）叶表型多态性的遗传学和生态生理学。

我们调查了遗传生态学和叶毛密度多态性的生理生态机制薄子木属recurvum钩。F。（桃金娘科）位于海拔3,000 m的Mt. 婆罗洲京那巴鲁。在同一种群中，叶片毛状体密度不同的各种表型同时出现，并且不同种群间共存表型的组成存在很大差异。我们通过从不同叶毛密度的多棵母树上播下种子进行了一个普通的花园实验。我们发现母树的青春期与后代之间存在显着的关系，这表明叶片毛状体的密度具有遗传基础。微卫星分析显示，在表型之间或群体之间的基因流没有障碍，并且在具有高基因流的表型的两个方向上的群体之间，中性遗传分化非常低。在短时期的干旱中，以短柔毛树为主的地点的土壤比以无毛树为主的地点的土壤干燥得多。在厄尔尼诺现象严重干旱的两个地点同时出现两种表型的同一地点，无毛乔木的死亡率比短毛乔木高得多（分别为13.7％和3.9％）。青春期个体的光合用水效率明显高于无毛个体。厄尔尼诺干旱可能会导致地点之间土壤水分的巨大差异，并且更大的干燥胁迫消除了无毛表型，这是自然选择分化形成青春期种群的一端。这些结果表明，塑造表型多态性的过程涉及强大的基因流以及正在进行的发散选择。