The factors that facilitate successful colonization of islands should be especially evident where the establishment filter is strongest. Colonizers of small, remote oceanic islands should be initially rare, extremely mate-limited and often without pollinators. Hence, plant communities on such islands should reflect an establishment history in which young ‘naturalized’ species are most likely to display self-compatibility and autonomous selfing, whereas ‘indigenous’ species may exhibit more diverse reproductive strategies. To test this prediction, we characterized breeding systems of 28 species on Pohnpei, in the Federated States of Micronesia, a group of remote Pacific islands that are considered a global biodiversity hotspot. Three families with both naturalized and indigenous species were selected—Fabaceae, Malvaceae and Melastomataceae. Measurements included field observations of dichogamy/herkogamy and floral attraction traits, pollen:ovule (P:O) ratios and experimental hand-pollinations for self-compatibility and pollen limitation. Phylogenetic generalized least squares analyses tested for trait correlations between naturalized and indigenous species. Flowers of all 28 species were bisexual, and pollinator attraction features were common. Pollen:ovule ratios ranged from 9 to 557 (median = 87), and all 11 hand-pollinated species were self-compatible. All species had >5 ovules and <3500 pollen grains per flower. Indigenous species did not differ significantly from naturalized species for any trait. There is a dearth of data from remote islands bearing on the question of establishment history. In this study, we inferred all species to have some degree of autogamy and indigenous species were no more likely than naturalized species to display outcrossing mechanisms. On Pohnpei, high ovule numbers, and the inaccessibility of wind pollination and obligate outcrossing strategies, reflect the importance of retaining reproductive assurance mechanisms in the face of pollinator uncertainty.

中文翻译：

---

归化与本土物种的育种系统为波纳佩岛上的贝克定律提供了支持

在设施过滤器最强的地方，促进岛屿成功殖民的因素应该特别明显。小而偏远的海洋岛屿的殖民者最初应该是罕见的，极其有限的伴侣，并且通常没有传粉者。因此，这些岛屿上的植物群落应该反映一种建立历史，其中年轻的“归化”物种最有可能表现出自我相容性和自主自交，而“本土”物种可能表现出更多样化的繁殖策略。为了检验这一预测，我们在密克罗尼西亚联邦的波纳佩对 28 个物种的繁殖系统进行了描述，该地区是一组被认为是全球生物多样性热点的偏远太平洋岛屿。选择了三个同时具有归化和本地物种的科——豆科、锦葵科和紫锥菊科。测量包括对二重性/雌雄同体和花卉吸引性状的现场观察、花粉：胚珠 (P:O) 比率以及自交亲和性和花粉限制的实验性人工授粉。系统发育广义最小二乘分析测试归化和本地物种之间的性状相关性。所有 28 种花均为两性花，传粉者吸引特征很常见。花粉：胚珠比率在 9 到 557 之间（中位数 = 87），所有 11 种人工授粉物种都是自交亲和的。所有物种每朵花具有＞5个胚珠和＜3500个花粉粒。土著物种与归化物种的任何性状都没有显着差异。偏远岛屿缺乏与建立历史问题有关的数据。在这项研究中，我们推断所有物种都具有一定程度的自交性，而本土物种并不比归化物种更有可能表现出异交机制。在波纳佩，高胚珠数量，以及风传粉和强制异交策略的不可接近性，反映了面对传粉媒介不确定性时保留生殖保证机制的重要性。