摘要
本文采用分支分类学中同源性状状态分析方法,在对沙棘属的20个同源性状进行状态分析和计算各类群演化指数的基础上,找出沙棘属的原始类群——沙棘和柳叶沙棘;结合对沙棘属各类群植物的径度、纬度和海拔三度空间的地理分布研究,对沙棘属原始类群生长发育所需的各生态因子最适量图的分析,以及果实中V_c含量变化的对比分析等,来探讨沙棘属植物的起源。认为沙棘属植物的起源地在东喜马拉雅至横断山之间。
The problems of origin of the genus Hippophae L. have been discussed in this paper. Firstly, based on the state analysis of 20 homologous characters, the evolution index of all 5 species and8 subspecies in the genus have been calculated by using the formula Id =d/cx 100% (Id-The
evolution index of taxon, d-The sum total of derived state characters, c-The sum total of
homologous characters. ). The data show that H. rhamnoides subsp. sinensis and H. salicifolia are the most primitive species, but H. thibetana is the most advanced species in the genus, secondly , the geographical distribution of the genus (for the convenience of studying the origin, the primitive subspecies-H. rhamnoides subsp. sinensis divided out of H. rhamnoides) and the right
amount equivalent lines diagram about the ecological factors, including annual solar radiation, annual cumulative temperature of ≥5℃ annual sunshine duration of ≥5℃ and annual precipitation, for H. rhamnoides subsp. sinensis have been analysed. As a result of the analysis, the origin of the genus is suggested: the region may lie between the East Himalayas and Hengduan Mountains. Finally, some physiological and biochemical properties of the genus and the trends of Vc content variation in its fruits, including the relation between Vc content and the evolution index of every species in the genus; the relation between Vc content of H. rhamnoides subsp. sinensis and North latitude degrees in Shanxi Province; and the relation between Vc content of H. rhamnoides subsp. sinensis and altitude in Qinghai Province, have been discussed. The conclusion is similar to the above result. All evidence demonstrate that the genus Hippophae L. originated in the middle-higher altitude area of the lower North latitude degrees. The region lies between the East Himalayas and Hengduan Mountains. The ancestral species of the genus Hippophae L. is a water-like mesophilous plant with few carpels and the developed horizontal roots.
基金
中国科学院系统进化植物学开放实验室资助项目
关键词
植物
沙棘属
同源性状
原始类群
Hippophae,Origin,Cladistic analysis,Geographical distribution,Ecological factor.
