Jiang Kai, Gao Hui, Chen Xiao Yong
School of Ecological and Environmental Sciences/Shanghai Key Laboratory of Urban Ecological Processes and Eco-Restoration, East China Normal University, Shanghai 200241, China.
Shanghai Chenshan Botanical Garden/Shanghai Chenshan Plant Science Research Center, Chinese Academy of Sciences, Shanghai 201602, China.
Ying Yong Sheng Tai Xue Bao. 2018 Feb;29(2):397-402. doi: 10.13287/j.1001-9332.201802.039.
Seagrasses are monocotyledons that grow in intertidal and subtidal zones. Seagrass beds are among ecosystems with the highest ecosystem service value. However, seagrass beds are rapidly decline due to anthropogenic disturbances and global climate change. Enhalus acoroides, a monoecious perennial species, is the largest seagrass in stature. It distributes in tropical regions, with Hainan Island as its northern limits. Clonal diversity and genetic structure of E. acoroides populations in Hainan Island were studied to facilitate its conservation and restoration. We used four polymorphic microsatellites to genotype samples collected from four extant populations. We found low clonal and genetic diversities within populations, consistent with the expectations of genetic structure in edge populations. A large range of genetic differentiation was found between these four populations, probably due to the large range of geographic distances between them and genetic drift by local extinction and recolonization. We found no sign of recent bottlenecks in all the populations, probably due to the within-population genetic diversity being too low to show obvious reduction even after bottlenecks. We proposed suggestions on population conservation for those with high priority. Given that seagrass bed had experienced rapid decline in recent years, strengthened conservation and ecological restoration are urgently needed.
海草是生长在潮间带和潮下带的单子叶植物。海草床是生态系统服务价值最高的生态系统之一。然而，由于人为干扰和全球气候变化，海草床正在迅速衰退。海菖蒲是一种雌雄同株的多年生物种，是体型最大的海草。它分布在热带地区，以海南岛为其北界。为了促进海菖蒲的保护和恢复，对海南岛海菖蒲种群的克隆多样性和遗传结构进行了研究。我们使用四个多态微卫星对从四个现存种群采集的样本进行基因分型。我们发现种群内的克隆和遗传多样性较低，这与边缘种群的遗传结构预期一致。在这四个种群之间发现了很大的遗传分化，这可能是由于它们之间地理距离较远以及局部灭绝和重新定殖导致的遗传漂变。我们在所有种群中都没有发现近期瓶颈的迹象，这可能是由于种群内的遗传多样性过低，即使在瓶颈之后也没有明显减少。我们针对优先级高的种群提出了种群保护建议。鉴于近年来海草床迅速衰退，迫切需要加强保护和生态恢复。
