Chromosome study on woody plants by young leaves and buds - especially on plants belong to Hamamelididae

本文对木本金缕梅科24科18科的核型进行了研究，以期有助于对染色体进化和科内、科间关系的认识。其中悬铃木科、金缕梅科、杜仲科、榆科、红叶藓科、胡桃科和杨梅科7个科的核形态学已有报道（或正在出版）。结果表明，各科属间间期、前期和中期的核形态及染色体数目具有相似的染色体特征。在中期，除杨梅科（Myricaceae）的染色体具中着丝粒外，金缕梅科（Hamamelididae）所有属的染色体具中着丝粒、近中着丝粒和近端着丝粒的频率不同。大多数科的间期核形态特征相似，但榆科的间期核有两种类型：简单色中心型和弥散复合色中心型。总之，本研究表明，如果可用的话，核形态学证据可以适当地纳入进一步细化金缕梅科内的超属分类。因此，有必要对更多属（科）、种进行进一步的核形态学研究。

Karyomorphology in eighteen families of twenty-four families belong to woody Hamamelididae were investigated in an effort to contribute to an understanding of chromosome evolution and inter- and intrafamilial relationships. In the eighteen families, karyomorphology of seven families : Platanaceae, Hamamelidaceae, Eucommiaceae, Ulmaceace, Rhoipteleaceae, Juglandaceae and Myricaceae, have been reported (or in press). The results showed that karyomorphology at interphase, prophase and metaphase, and chromosome number within the genus of respective family showed similar chromosome features. At metaphase all the genera investigated of woody Hamamelididae, however, have chromosomes with median centromeres, those with submedian centromeres and those with subterminal (or terminal) centromeres at different frequencies, excepting that Myricaseae (Myrica) has chromosomes with median centromeres. The morphology at interphase of most families showed similar features, while the Ulmaceae had two types of interphase nucleus ; the simple chromocenter type and the diffuse-complex chromocenter type. In conclution, the present study suggests that, if available, karyomorphological evidence can properly be incorporated in further refining supergeneric classification within Hamamelididae. A further karyomorphological study on more genere (families) and species is necessary for the purpose.