The Origin and evolution of multiple polyploid lines in the natural populations of Dumortiera hirsuta.

通过使用染色体分析、同工酶多态性和c-DNA序列，我们发现了以下几点；我们在东亚和东南亚的毛斑蝶单倍体中可以识别出7个以上的生物单位。仅凭它们的外表形态很难区分它们。此外，多倍体与任何单倍体植物都有遥远的遗传关系。在同工酶技术检测的12个位点中，几乎所有的二倍体和三倍体都表现出固定的杂合性。因此，我们认为二倍体是异源多倍体。这意味着多倍体起源于上述单倍体的不同生物单位之间的杂交。我们在日本（本州、四国、九州、琉球）、中国南方、马来半岛和婆罗洲发现了三倍体的Dumortiera hirsuta。在日本和中国发现的三倍体不能通过等位酶变异来区分，因此可以被视为属于相同的生物单位。马来半岛的和婆罗洲的分别不同于日本和中国的。在所有单倍体和多倍体并排生长的种群中，单倍体的cp-DNA类型与多倍体的cp-DNA类型不同。因此，在本研究中我们不能确定多倍体的起源，留待将来的研究。

By the use of chomosome analyses, allozyme polymorphisms, and c-DNA sequneces, we have found the following points ;1. We can recogninize more than seven biological units in the monoploid of Dumortiera hirsuta in the Eastern and Southeastern Asia. It is difficult to distinguish them only by their outer morphologies. In addition, polypolids show distant genetic relationships to any of the monoploid plants.2. Almost all cases, diploids and triploids of Dumortiera hirsuta show fixed heterozygosity in several loci among 12 loci examined by allozyme technique. Thus, we considered that diploids are allopolyploids. This means that polyploids have originated by hybridization between different biological units of monoploids described above.3. We found triploid Dumortiera hirsuta in Japan (Honshu, Shikoku, Kyushu, Ryukyu), Southern China, Malay Penisula, and Borneo. Triploids found in Japan and China cannot been distiguished by allozyme variation and thus can be treated as belonging to the same biological units. Those of Malay Penisula and Borneo are different from Japanese and Chinese one, respectively.4. In the all populations where monoploids and polyploids grow side-by-side, cp-DNA type of monoploids differs from that of polypolids. Therefore, we cannot asertain the origin of polyploids in this study and left for future examination.