Molecular population genetic study on regeneration processes of disturbed mangrove forests in Vietnam

红树林是热带和亚热带潮间带森林群落的组成植物，在世界上约占2亿公顷的面积。在这项研究中，我们调查了越南红树林的生态系统，这是严重破坏的越南战争，但现在再生和分析的更新过程中使用群体遗传学方法。主要研究结果如下：1.以越南北方南定省秋茄人工林为研究对象，探讨了林龄和淹水对红树林土壤碳积累的影响。我们发现，种植园土壤中的碳积累强烈地依赖于林分年龄和淹没频率。2.我们利用各种标记研究了越南红树林的遗传变异的数量和模式。对秋茄和白骨壤的AFLP和微卫星标记分析表明，这两个物种的南方和北方种群之间存在遗传分化。事实上，秋茄南方和北方之间的遗传分化程度如此之大，以至于这两个种群似乎来自两个不同的物种。此外，我们还利用叶绿体标记matK研究了红树林的遗传分化，并添加了一个常见的物种-总状假单胞菌（Lumnitzera racemosa），得到了与核标记相似的结果，但总状假单胞菌的遗传分化较小，在此基础上，我们考虑了如何利用红树林自身的再生能力恢复红树林生态系统。

Mangroves are constituent plants of tropical and subtropical intertidal forest communities and they occupy about 200 million ha of areas in the world. In this study, we investigated the ecological systems of Vietnamese mangrove forests which were heavily damaged by the Vietnam War but are now regenerating and analyzed the regenerating process using population genetic approaches. The following results were obtained.1.An investigation was conducted on Kandelia candel plantations in Namdinh Province, Northern Vietnam to elucidate the influences of stand-age and inundation on carbon accumulation in mangrove soil. We found that carbon accumulation in the soil of a plantation strongly depended upon both stand-age and inundation frequency.2.We investigated amounts and patterns of genetic variation in mangroves of Vietnam using various markers. For K.candel and Avicennia marina, AFLP and microsatellite markers revealed that there were genetic differentiation between southern and northern populations of the two species. In fact, the extent of genetic differentiation between south and north in K.candel was so large that the two populations seemed to be from two separate species. We also used a chloroplast marker, matK, to investigate genetic differentiation adding one more common species, Lumnitzera racemosa, and obtained similar results as those based on nuclear makers except that little variation was found in L.racemosa.Based on these results, we considered how to recover mangrove ecosystems utilizing mangrove's own regenerating capability.