Flowering, pollination and pollinators of mangroves in Okinawa

这项研究的持续时间为3年，2002年至2004年。主要研究地点是日本冲绳县健市大久比河河口的红树林。如有可能，每周进行定期观察和样品收集。有时，特别是在2004年，台风事件使取样变得困难。木榄全年都有花期，秋茄一年一次。虽然B.gymnorrhiza全年开花，但成功的结果仅限于6月至12月期间。1 ~ 5月形成的花花药不常开放，花粉萌发能力很低，用花粉袋覆盖B.gymnorrhiza的花，花瓣开放率低于8%.相比之下，在自然条件下花瓣开放率约为94%。较大的传粉者，如Sphex argentatus和Zosteropus japonica loo ...更多信息 Escherichiensis有助于诱导花瓣完全开放并促进花粉从花药中传播。然而，非常小的昆虫（包括蛾）如Macroglossum mediovitta的访花未能帮助花瓣开放。这表明，它们作为传粉者的作用并不那么重要相比，那些大的传粉者。人工花粉袋处理（防止异花授粉）的B.gymnorrhiza花的花瓣开放率约为8%。在这些有限的花瓣开口中，可以识别出一些由自花授粉引起的胚珠的扩展。这表明在自然条件下，一些自花授粉是可能的。然而，总的来说，木本植物的自花授粉率似乎很小。然而，微卫星分析的结果也表明，B.gymnorrhiza和K.candel的自花授粉率相对较高，因此这些结果表明，具有一定自花授粉能力的红树林树种，如B.gymnorrhiza和K.candel，具有迁移容易的优势，一旦进入新的生态环境，能够比其他缺乏自花授粉能力的红树林物种更有效地维持它们的群落。少

The duration of this research was 3 years, 2002 to 2004. The main research sites were mangrove forests at the mouth of Okukubi River, Kin, Okinawa, Japan. Regular observations and sample collections were made when possible at weekly intervals. At times especially during 2004, typhoon events made sampling difficult. Bruguiera gymnorrhiza flowing phenology occurred throughout the year, while that of Kandelia candel was once a year. Although B.gymnorrhiza flowered throughout the year, successful fruiting was restricted to the period June to December. Anthers of flowers formed from January to May did not always open and pollen germination abilities of these flowers were very low.When flowers of B.gymnorrhiza were covered with pollen bags to prevent visits by pollinators, rates of petal opening were less than 8 %. In contrast, rates of petal opening under natural conditions were approximately 94 %. Visits to flowers by larger pollinators, such as Sphex argentatus and Zosteropus japonica loo … More chooensis, helped to induce full petal opening and enhance pollen dispersal from anthers. However, flower visiting by very small insects (including moths) such as Macroglossum mediovitta, failed to help petal opening. This suggested that their roles as pollinators were not so important compared to those of lager pollinators. Under the artificial pollen bag treatment of B.gymnorrhiza flowers (prevent cross-pollination) petal-opening rates of such flowers to disperse pollen were approximately 8 %. Within these limited petal-openings some expansions of ovules caused by the self-pollination could be recognized. This indicates that some self-pollination might be possible under natural conditions. Nevertheless, in general, it seems that self-pollination rates of woody plants are small. However, results of microsatellite analyses also suggested that relatively higher self-pollination rates can occur in B.gymnorrhiza and K.candel.Thus these results suggest that mangrove tree species having some self-pollination abilities, such as B.gymnorrhiza and K.candel, had some advantages of easier migration and, once in a new ecohabitat, are able to maintain their communities more efficiently than other mangrove species that lack these self-pollination abilities. Less