Biosystematics of Indo-Chinese Flora

1994年6月，岩月光一访问巴黎自然历史博物馆，根据标本室保存的标本，对《印度支那植物群》进行了调查。1994年12月至1995年1月，岩月光、村上隆和横山健（该项目的助理成员）访问了越南、老挝和泰国。我们与C.Phengklai（泰国）、B.Svengsukusa（老挝）和N.N.Thin（越南）合作，收集了2000多份植物标本和大量DNA样本。今年，我们在越南北方的考察中取得了重要成果。这个地区是植物地理上重要的地方，特别是当我们考虑日本和中国植物的物种形成时。在种子植物方面，我们采集了桑科、天南星科、茜草科、山茶科和菊科等在该季节开花和结果的植物标本。本文报道了采自沙巴山林的天南星属一新种。在中国尚未发现与该新种有亲缘关系的种，因此在研究天南星属植物的物种形成时具有重要的参考价值。在蕨类植物方面，我们收集了许多蕨科的膜蕨属和网蕨属的标本。这两个类群的形态都很简单，很难辨认。因此，我们在发现这些植物的每个地方收集了DNA样本以及植物标本，并在回到日本后进行了详细的比较。我们已经测定了其中一些样品的rbcL基因的核苷酸序列，并发现了几个分子上可区分的分类单位。通过对我们在印度支那采集的标本的进一步分析，将有助于我们对该类群的深入了解。

In June, 1994, K.Iwatsuki visited Paris Natural History Museum and investigated "Flora of Indo-China" based on the specimen deposited in their herbarium. During December, 1994 - January, 1995, K.Iwatsuki, N.Murakami and J.Yokoyama (assistant member of this project) visited Vietnam, Laos, and Thailand. Collaborating with C.Phengklai (Thailand), B.Svengsukusa (Laos) and N.N.Thin (Vietnam), we collected more than 2000 numbers of herbarium specimens and many DNA samples.This year, we got important results from our expedition to Northern Vietnam. This area is plant geographically important place, especially when we consider speciation of Japanese and Chinese plants. However, this area has not been well botanized and thus our expedition can contribute to great advances in understanding of the Flora and its evolutionary origin.For seed plants, we collected many specimen of Moraceae, Araceae, Rubiaceae, Cameliaceae and Compositae which had flowers and fruits in that season. We collected a new species of Arisaema (Araceae) from the mountain forest of Sapa. No related species to the new species have ever been collected in China, and thus is valuable when we consider speciation of Arisaema. Our study on these herbarium specimens are in progress.For ferns, we collected many specimens of Hymenasplenium and Neottopteris (Aspleniaceae). Both of the groups are very simple in morphology and hard to recognize the species. Therefore, we collected DNA samples as well as herbarium specimens from every localities where we found these plants, and made detailed comparison between them after we came back to Japan. We already determined nucleotide sequences of rbcL gene from some of these samples, and found several molecularly distinguishable taxonomic units. Further analyzes on our samples and specimen from Indo-China will lead us to deep understanding of the group.