Seed dispersion dynamics and population genetics of mangroves in Okinawa

红树林分布在热带的潮间带。种子和繁殖体的传播主要依靠潮汐，这种传播方式与陆生植物不同。为研究分布于日本冲绳琉球群岛的部分红树林树种的群体遗传动态，以白骨壤、木榄和红海榄为材料，利用微卫星或SSR标记分析了其群体遗传变异。为优化这3个树种的DNA提取条件，对十六烷基三甲基溴化铵（CTAB）法和冰冷缓冲液法进行了比较，改良CTAB法和Dneasy Plant Mini Kit（Quiagen）法提取的DNA产量较高。对于. marina为材料，设计了7对引物，对琉球群岛7个居群的遗传变异进行了分析。冲绳7个群体的杂合度（He）在0.000 ~ 0.078之间。结果表明，阿联酋和马尔代夫7个居群的异花授粉率低于4个居群。

Mangroves are distributed at inter-tidal zone in tropics. Seeds and propagules are dispersed mostly by tides, and this seed dispersion manner is different from it of terrestrial plants. The purpose of the study is to investigate dynamics of population genetics of some mangrove tree species distributed in Ryukyu Islands, Okinawa, Japan.Microsatellites or simple sequence repeats (SSRs) were applied as DNA markers to Avicennia marina, Buruguiera gymnorrhiza and Rhizophora stylosa to analyze genetic variation. To optimize DNA isolation condition for these three tree species, several methods such as Cetyl-trimethyl-ammonium bromid (CTAB) method and Ice-cold buffer method were tested, and modified CTAB method and Dneasy Plant Mini Kit (Quiagen) showed the reliable DNA yield.Twenty-four microsatellite primers were designed for Rhizophora sylosa, and among them, 8 primers were used but genetic variation was small. For A. marina, 7 designed primers were applied to analyze genetic variation of 7 populations in Ryukyu Islands. Hetetozygosity (He) of 7 populations in Okinawa was between 0.000 and 0.078. It suggested that cross-pollination rates of 7 populations were smaller than that of 4 populations in the United Arab Emirates and Maldives.