20种山茶科植物的叶表皮微形态研究

为解决一些山茶科(Theaceae)的分类学问题,该研究在光学显微镜下对山茶科2亚科6属共20种植物的13种叶表皮微形态特征进行了观察,并利用聚类分析和主成分分析对这些特征进行分析,为山茶科的科学分类提供参考资料。结果表明:(1)山茶科20种植物的13种叶表皮微形态特征能够区分种间差异和分类等级,显示了比较全面的分类价值。(2)基于微形态特征的聚类分析和主成分分析结果显示,20个种分为2个大类群以及10个分支,很好地区分了山茶亚科(Theoideae)与厚皮香亚科(Ternstroemoideae),并将大部分分类地位相近的物种归类到一起,较好地反映了物种之间的亲缘关系。(3)该研究结果支持将小黄花茶组(Sect.Luteoflora)作为独立的一个组;支持将重庆山茶(Camellia chungkingensis Chang)从瘤果茶组(Sect.Tuberculata Chang Tax.)中分离;支持将山茶亚科与厚皮香亚科划分为两个较大类群,认为将厚皮香亚科并入五列木科(Pentaphylacaceae)的观点还有待更多实验证据的支持。

Study on Leaf Epidermal Micro morphology of 20 Species of Theaceae

To solve some taxonomic problems of Theaceae, 13 leaf epidermal micro morphology characters of 20 species, which are from 2 subfamilies and 6 genera of Theaceae, were observed under light microscope and used for the cluster analysis and principal component analysis, providing reference to scientifical classification of Theaceae. The result illustrated that: (1) the 20 species was well distinguished by the 13 characters and different characters could be used to differentiate various ranks of taxonomic taxon, which showed all around taxonomic value. (2) The cluster analysis and principle component analyses based on micro morphology characters divided the 20 species into 2 clades and 10 isolates, suggesting that the taxonomy system could well distinguish Theoideae and Ternstroemoideae, and mainly group species with close taxonomic status together, which preferably reflected the relationships between species. (3) This study offered evidence of leaf epidermal micro morphology for the independence of Sect. Luteoflora and supported the segregation of Camellia chungkingensis from Sect. Tuberculata Chang Tax. Besides, this study indicated that dividing Theoideae and Ternstroemoideae into 2 clades was logical, but the viewpoint that Ternstroemoideae and Pentaphylacaceae should be clustered together needs more proof.