摘要
山茶属Ｃａｍｅｌｌｉａ植物在其进化过程中，以雄蕊不定数、在某些类群中存在心皮离生至合生的中间过渡，认为是山茶科中较原始的一属，分布于亚洲东部和东南部，中国长江以南广袤的亚热带地区是该属的现代分布中心中南半岛和我国云南、广西南部的热带地区种类虽少，却集中了本属原始或较原始的类群和种类。本属演化上的近缘属或姐妹群──核果茶属Ｐｙｒｅｎａｒｉａ（包括石笔术属Ｔｕｒｃｈｅｒｉａ）分布区大致与本属相似，其原始（子房５室，心应先端多少分离，花柱离生）的种类也分布于此，它们可能同出于一个心皮离生的古老祖先，即生长于亚洲古热带森林环境中的类似于五桠果属（Ｄｉｌｌｅｎｉａ）的原始山茶科植物，上述地区是该属的早期分化中心和起源地，大约在白垩纪特提斯海（古地中海）东岸的劳亚古陆和冈瓦纳古陆接触地带由原始五桠果类植物演化而来。山茶属植物自热带亚洲起源和分化发生后，向四周辐射状扩展，在亚洲大陆，类群和种类明显表现出由南向北、从热带向亚热带分化和替代的规律。在漫长的进化过程中，经历第三纪以来地史和古气候的变迁，分化发展为具花便和花梗强烈缩短变无梗的两个演化枝，分道扬镳平行发展，两枝在演化上相似地表现出雌、雄蕊数目的减少及合生水平的提高?
it is regarded that genus Camellia with indefinite number of stamins and especially 5nearly free to variously incomplete connated carpels from a few section is assumed to be the primitive genus in Theaceae. The evolution and distribution of this genus are discussed. The results are summarized as follows f (1) According to the morphological characters of main organs (flower and fruit), a taxonomic system consisted of 2 subgenera and 14 sections, including 1 new section are presented here. (2) On the basis of the system mentioned above and the analysis of all the morphological characters. the evolutionary tendency of genus Camellia including two phylogenetic branches are discussed. Sect. Piquetia with 3￣5 flowered short raceme and 5 nearly free carpels is considered as the most primitive group. Sect. Archecamellia, Heterogenea and StereocarPUs are more primitive groups, while Sect. Theopsis with only IAilocule fertile fruit and Sect. Calpandria with complete connate filament-tube are the most advanced groups in this genus. Concerning the evolution of Theaceae, the relationshps between genera Camellia and Pyrenaria (including Tutcheria) are closely related, they may be originated from a common ancestor in the phylogenesis. (3) The genus Camellia is only distributed in the east and southeast Asia, from 7 degrees south latitute to 35 degrees north latitute, 80 to 140 degrees east logititute. The whole genus contains 125 species, about 104 species are distributed in China, among all species more than 80% are concentrated in the south of Yangtze river. Where a vast subtropical region is cosidered to be the center of distribution of this genus. In accordance with the distribution of those more primitive groups and the closely related genus Pyrenaria in evolution, they could be originated together from indochina Peninsula and the neighbouring places south of Yunnan and Guangxi of China under the tropical forest environment, probably in Crateceous period.
出处
《云南植物研究》
CSCD
1996年第1期1-13,共13页
Acta Botanica Yunnanica
基金
国家自然科学基金
关键词
山茶科
山茶属
进化
分布
Camellia, Evolution, Distribution
