Graduate School of Human and Environmental Studies, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan; Agricultural and Forestry Office, Hyogo Prefectural Government, Asago 669-5202, Japan; Division of Ecological Restoration, Museum of Nature and Human Activities, Hyogo, Sanda 669-1546, Japan; and Makino Herbarium, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan.
Am J Bot. 2006 Dec;93(12):1852-8. doi: 10.3732/ajb.93.12.1852.
Climate changes during glacial periods have had significant effects on the present geographic distribution of plant species. To elucidate the evolutionary history of a plant species with a disjunctive distribution, we investigated the geographic distribution patterns of cpDNA haplotypes in Photinia glabra (Rosaceae) growing in broadleaved evergreen forests in Japan. We examined cpDNA in 42 populations of P. glabra sampled over a geographic range that included Kinki and its surrounding areas and the disjunctive regions in the Amakusa Islands. Both areas had unique cpDNA haplotypes. Moreover, the AMOVA revealed that a large proportion of the total variance (51%, P < 0.001) could be explained by differences among these regions. These results suggest a past fragmentation of this plant species into two separate refugia: southwestern Kyushu and Kinki, including the surrounding area, during the Quaternary glacial periods. A particularly interesting result was that in the southern disjunct distribution in the Amakusa Islands, the genetic subdivision (Φ(CT) = 1.00, P < 0.001) appears to lie between the populations from nearly contiguous islands located across a fairway only approximately 80 to 150 m in width.
在冰期，气候变化对现今植物物种的地理分布有重大影响。为了阐明具有间断分布的植物物种的进化历史，我们研究了在日本阔叶林生长的光叶石楠（蔷薇科）的 cpDNA 单倍型的地理分布模式。我们研究了在包括近畿及其周边地区和分布在天草群岛的间断地区的地理范围内采样的 42 个光叶石楠种群的 cpDNA。这两个地区都有独特的 cpDNA 单倍型。此外，AMOVA 表明，这些地区之间的差异可以解释总方差的很大一部分（51%，P < 0.001）。这些结果表明，在第四纪冰期，该植物物种曾被分割成两个独立的避难所：西南九州和近畿地区，包括周边地区。一个特别有趣的结果是，在天草群岛的南部间断分布中，遗传分裂（Φ(CT) = 1.00，P < 0.001）似乎位于仅宽约 80 至 150 米的航道上的几乎相邻岛屿的种群之间。
