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。本研究以越南红树林为研究对象，利用种群遗传方法分析了越南红树林在越南战争中遭受的严重破坏，目前正在恢复的生态系统。得到了以下结果：以越南南定省红树人工林为研究对象，探讨了林龄和淹没对红树土壤碳积累的影响。研究发现，人工林土壤碳积累与林分和淹水频率密切相关。我们利用各种标记研究了越南红树林遗传变异的数量和模式。AFLP和微卫星标记显示，两种植物的南北居群存在遗传分化。事实上，坎德尔的南北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研究了另一种常见物种总形Lumnitzera racemosa的遗传分化，得到了与基于核制造者的结果相似的结果，除了总形l.a racemosa的差异不大。基于这些结果，我们考虑了如何利用红树林自身的再生能力来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.