Demographic genetics on the temperate Asiatic elements in North America

为了了解北美温带亚洲成分的遗传分化，以开花物候观察、育种试验和等位基因多态为遗传标记，研究了几种草本植物地方居群的种群遗传学亚结构。由于该物种广泛生长在不同的海拔高度，不同海拔的融雪季节差异对种群之间的开花物候和基因流动以及随后的当地种群遗传结构都有显著的影响。对北美东部三种不同繁殖方式的延龄草的繁育系统和种群遗传结构进行了研究。延龄草主要通过种子繁殖，具有较高的遗传多样性和花序。另一方面，尽管有证据表明延龄草营养枝频繁产生，但它表现出高度的遗传多样性。因此，不仅要从等位酶变异的角度研究百合的遗传多样性，而且要对自然种群进行开花物候观察和育种实验。此外，还测定了亚洲百合属(Clintonia)(5种)和百合属(Lilium)的两个叶绿体基因matK和rbcL的序列，并阐明了东亚百合属和北美百合属的亲缘关系和系统发育。

In order to understand the genetic differentiation of the temperate Asiatic elements in North America, demographic genetics substructuring of the local populations were investigated for several herbaceous plant species, based on observation of flowering phenology, breeding experiments and allozyme polymorphisms as genetic markers.In the western North America, we have focused on Erythronium grandiflourm occurring in Rocky Mountains. Since this species widely grows at different elevations, differences in snow melting season at each elevation showed significant effect on flowering phenology and gene flow among populations and subsequent local population genetics structures. In the eastern North America, the breeding system and population genetic structure of three Trillium species which have different modes of reproduction, were studied. Trillium erectum, which reproduce mainly by seeds, represented high genetic diversity as well as floral colores. On the other hand, in spite of the evidence of frequent production of vegetative offshoots, Trillium ludovicianum showed high genetic diversity. It was suggested that it is important and essential not only to investigate genetic diversity in terms of allzyme variations, but also to perform observation of flowering phenology and breeding experiments with natural populations.Furthermore, two chloroplat genes, matK and rbcL, were sequenced for the genus Clintonia(5 species)and Lilium(41species), and the affinity and phylogeny of the disjunct eastern Asiatic and North American Liliaceous group was also clarified.