Chheang Pisal, Hembry David H, Yao Gang, Luo Shi-Xiao
Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China.
University of Chinese Academy of Sciences, Yuquanlu, 19A, Beijing, 100049, China.
Plant Divers. 2021 Jul 16;44(2):191-200. doi: 10.1016/j.pld.2021.07.001. eCollection 2022 Mar.
(Phyllanthaceae; leafflower trees) is a genus of trees which is widely reported to be pollinated by leafflower moths (Gracillariidae: ) in temperate and subtropical Asia, Australia, and the Pacific islands. However, the pollination ecology of is not well described from tropical Asia, the region where it is most species-rich at both local (≤9 spp.) and regional (~200 spp.) scales. Here we report investigations of pollination biology and species-specificity of five species in tropical Southeast Asia (Cambodia). Through nocturnal observations and fruit dissections, we find that at least three and likely five species in Cambodia are pollinated by seed-parasitic leafflower moths. We find no evidence that any of these leafflower moths are non-mutualistic parasites, despite known examples of such parasites of this mutualism elsewhere in Asia. While the presence of a single larva in a fruit results in only a fraction of seeds being consumed, the presence of more than one larva per fruit-a frequent occurrence in some species-can result in almost all seeds within the fruit being infested. Multilocus phylogenetic analysis indicates that there are five different minimally monophyletic leafflower moth clades, each of which pollinates a unique host species. Our results indicate that in its center of diversity in tropical Asia this system is an obligate pollination mutualism as previously described at the global margins of its distribution. These findings provide insights into the processes that generate and maintain biodiversity and maintain mutualism stability in plant-insect interactions in this biodiversity hotspot.
（叶下珠科；叶下珠属树木）是一个树木属，在亚洲温带和亚热带地区、澳大利亚以及太平洋岛屿，有广泛报道称其由叶下珠蛾（细蛾科：）授粉。然而，在热带亚洲地区，叶下珠属的授粉生态学尚未得到充分描述，而该地区是叶下珠属在局部（≤9种）和区域（约200种）尺度上物种最为丰富的地方。在此，我们报告了对热带东南亚地区（柬埔寨）五种叶下珠属物种的授粉生物学和物种特异性的调查。通过夜间观察和果实解剖，我们发现柬埔寨至少有三种、可能有五种叶下珠属物种由种子寄生的叶下珠蛾授粉。我们没有发现任何证据表明这些叶下珠蛾中有任何一种是非互利共生的寄生虫，尽管在亚洲其他地方已知存在这种共生关系的此类寄生虫实例。虽然果实中存在单个幼虫只会导致一小部分种子被消耗，但每个果实中存在多个幼虫——在某些物种中经常出现——可能会导致果实内几乎所有种子都被侵染。多位点系统发育分析表明，有五个不同的最小单系叶下珠蛾分支，每个分支为一个独特的叶下珠属宿主物种授粉。我们的结果表明，在热带亚洲的多样性中心，这个系统是一种专性授粉互利共生关系，正如之前在其分布的全球边缘地区所描述的那样。这些发现为在这个生物多样性热点地区的植物 - 昆虫相互作用中产生和维持生物多样性以及维持互利共生稳定性的过程提供了见解。
