摘要
根据被子植物大系统的资料和形态学观察确定了大凤子科山桐子属为杨属的外来群,即假设的祖先类群,借以确定杨属性状的极性,通过简约性分析构建了杨属有根的Wagner树,把杨属的五个组分为演化趋势上的三支:第一支为最原始的白杨组;第二支为变异较大的大叶杨组和青杨组;第三支是歧化的黑杨组和胡杨组。
The present paper deals with a cladistic analysis of 15 species of the genus Populus using 23 characters (13 vegetative and 10 reproductive).Idesia, a genus of Flacourtiaceae, is adopted to be the outgroup based on recent data of angiosperm macrosystem as well as evidence of morphological characters. The characteristic polarities of the species of Populus involved are then determined by employing the recent common anesstor (ANC)-Idesia. The Wagner tree is constructed on the basis of parsimonious analysis. The result indicates that there are three evolutionary lines in the genus Populsu: the first is the most primitive Sect. Lence; the second, which includes Sect. Leucoides and Sect. Tacamahaca, is considered as the most variable one; and the third includes the most advanced Sect. Aigeiros and Sect. Aigeiros and Sect. Turanga. A close relationship between Sect. Leuce and Sect. Leucoides is recognized. Sect. Turanga is the most advanced one in Populus. The morphological variation and geographic distribution of Sect. Tacarrahaca in China are discussed.
出处
《植物研究》
CAS
CSCD
北大核心
1990年第1期69-76,共8页
Bulletin of Botanical Research
