竹类果实胚体的比较解剖与系统分类

COMPARATIVE ANATOMY OF BAMBOO EMBRYO AND THEIR SYSTEMATIC CLASSIFICATION

The anatomical types of the embryo of the bamboo fruits are variable and complicated. A lot of characters such as the anatomical types of the embryo, the angles between the radicle and scutel, between the plumule and scutel, the curve degree of the embryo, the extension degree of the mesocotyl, and the size, pattern of the scutel, are more or less different among the bambotaxa. Most of those varities tally with the classification based on morphological characters, on the other hand, some contradictions and overlaps exit. Some taxa of bamboos with radicle with acute angle or parallel to scutel, such as Thyrsostachys siamensis, Phyllostachys pubenscens, P. heteroclada, Bashania fangiana, B.fargesii, belong to the primitive groups, some others, for instances, Chimonobambusa hejiangensis, Sinobambusa sichuanensis, Fargesia denudata are comparativly advanced, since they have radicle with large angle or perpendicular to scutel, some species, e. g., Chimonobambusa hejiangensis, Sinobambusa sichuanensis, Qiongzhuea rigidula, have embryo curved together into reduplicative form and they are comparatively more advanced than others. The extension degree of the embryonal axisis a value in evolution. Since the embryo, especially the mesocotyl, of Fargesia spesacea and F. denudata, are obviously elongated, they are possibly superior group, conversely, taxa with short mesocotyl are primitive group.