Effects of reproductive systems on creation and maintenance of species diversity in Dipterocarpaceae

在马来西亚婆罗洲沙拉越的热带雨林中，研究了龙心科植物的遗传结构和生态位分化，探讨了龙心科植物高度多样性的形成和维持机制。主要研究结果如下：摘要对蜂传粉的新兴自由种芳香木虱（Dryobalanops aromatica）进行了新的微卫星遗传标记。利用这些标记，对沙拉越兰伯尔山国家公园52 ha长期生态样地一个种群进行了遗传结构和生殖生态学研究。结果表明，该种群异交率高（0.72 ~ 1.00），花粉传播距离长（平均179.6 ~ 355.7 m）。研究群体的成虫没有明显的空间遗传结构，这可能与高异交率和低花粉传播距离有关。在同一森林中，甲虫传粉的树属（Shorea curtisii）均未显示出明确的空间遗传结构。在沙捞越区域尺度上存在空间遗传结构，且沙捞越中部的马来半岛单倍型多样性最高，在该地区发现了一个祖先单倍型，表明沙捞越中部是沙捞越树属6个物种分化的中心。2 .林内两个同域种（d.a aromatica和D.lanceolata）的遗传差异最大。完成兰比尔山国家公园52公顷长期生态地块第三次普查。测量所有直径大于1 cm的树木，并建立数据库。利用该数据库对788种乔木进行了生境生态位分析，其中包括双龙心科树种。在被分析的物种中，88%的物种是栖息地专家，其空间分布明显偏向于物种特定的栖息地。双龙心科各种间的生境分化程度显著高于所有种对，表明双龙心科是包含生境高度分化物种的科。少

Genetic structure and niche divergence of Dipterocarpacea were studied in a tropical rain forest in Sarawak on the Island of Borneo, Malaysia in order to discuss the mechanisms of creation and maintenance of the high species diversity of Dipterocarpaceae. Major results are the followings.1. Novel microsatellite genetic markers were developed in Dryobalanops aromatica, a bee-pollinated emergent free species. Using these markers, genetic structure and reproductive ecology of D.aromatica were studied for a population in a 52-ha long-term ecological plot in Lambir Hills National Park Sarawak Estimated outcrossing rates were high (0.72-1.00), and pollen dispersal distances were fairly long (mean : 179.6-355.7 m). No clear spatial genetic structure was found in the adults of the study population probably due to the high outcrossing rates and log pollen dispersal distances. Shorea curtisii, a beetle-pollinated species, neither showed clear spatial genetic structure in the same forest.2. Neste … More d clade analysis based on difference in chloroplast DNA sequence among 6 species of the genus Dryobalanops revealed a presence of spatial genetic structure at the regional scale in Sarawak and the Malay peninsular Haplotype diversity was highest at the central part of Sarawak, and an ancestral haprotype was found in this region, suggesting that the central Sarawak was the center of the divergence of DryobaLanps. Two sympatric species of the Lambir forest, D.aromatica and D.lanceolata, were gnenetically most apart within the genus.3. The third census of the 52-ha long-term ecological plot of Lambir Hills National Park was completed. All the trees with 1 cm dbh and larger were measured, and a database was established. Using this database, habitat niche analysis was conducted for 788 tree species including species of Dipterocarpaceae. Of the species analyzed, 88% were habitat specialists whose spatial distributions were significantly skewed to species specific habitats. Degree of habitat divergence between species of Dipterocarpaceae was significantly higher than that for all species pairs, suggesting that Dipterocarpaceae was the family that included highly divergent species in terms of habitat. Less