摘要
本文在栎属(Quercus)系统演化、化石历史和现代分布研究的基础上,讨论了中国栎属的起源、演化和现代分布格局形成的规律。栎属的现代分布中心在印度支那植物区,而这个分布中心就是栎属的起源地;加勒比植物区是栎属的次生分布中心。栎属于古新世早期在上述起源地,起源于三棱栎。栎属起源以后分化出青冈亚属和栎亚属,前者限于东亚、东南亚分布,后者广布于北温带。栎亚属形成以后,分化出高山栎组和巴东栎组两个原始类群,并通过巴东栎—子栎的路线演化出落叶栎类。北美的栎类有两个来源,一是通过高山栎、冬青栎演化而成;另一群源于欧亚的落叶栎类。
Origin, phylogeny and dispersal of Quercus from China were discussed based on studies of phylogeny, fossil history and modern distribution of Quercus. According to Takhtajan's view point of regionlizatiton of the world flora, a number of species in every region of the world were counted as follows: Caribbean region with 134 species belonging to one subgenus and three sectitons (3/1), Indo-Chinese region 118(3/2) and east Asian region 97(3 / 2). Above regions are abundant in a number of species and can be considered as the centres of majority. In conjunction with considering their phylogenetic relationships and fossil history Indo-Chinese region would be however the centre of distribution and speciation and could be original place of Quercus.
Original time of Quercus was suggested in early Plaeogene based on the fossil history of Quercus. Trigonobalanus has been recognized as probable ancestor of Quercus.
After the emergence of Quercus on the earth, two large groups, subg. Cyclobalanopsis and subg. Quercus were first derived. Subg. Cyclobalanopsis mainly developed and dispersed insoutheasten Asian. They dispersed not beyoned 'the line of Wallace 'forward to southeast and reached the line of Qinling moutain to Huaihe river forward to north. Two groups were evolved, sect. Brachylepides and sect. Engleriana, after the emergence of subg. Quercus. Sect. Brachylepides, the oldest group in subg. Quercus, mixed in broad evergreen forest at first and then developed and becomed dominant in Hengduan Mountain with the Tethys withdrawing and Himalayas rising since the Miocene because of adapted to dry enviroment. Deciduous oaks could be evolved from sect. Echinolepides via sect. Engleriana and then two sections, sect. Quercus and sect. Aegilops, were derived. These sections dispersed in North Temperate, reaching 62 degrees north latitude in northwesten Europa and 52 degrees north latitude in northeast. Deciduous oaks dispersed to subtropical area and tropical mountains when the glacier came and climate became cold in the earth. Oaks dispersed to North America by two routes: 1) from Tethyan region migrating across the middle Atlantic before the late Eocene, this group could be sect. Protobalanus, evolving from sect. Brachylepides via Q.ilex.This section is held to be primitive among American oaks; 2) across the Asia-Bering land bridge after the Miocene. Sect. Quercus could take this route.
In short Quercus was evolved from Trigonobalanus in tropic mountains of Indo-Chinese region in the early Paleocene and then dispersed to other areas from this region.
出处
《云南植物研究》
CSCD
1992年第3期227-236,共10页
Acta Botanica Yunnanica
基金
国家自然科学基金资助项目
关键词
壳斗科
栎属
起源
演化
分布
区系
Fagaceae
Quercus
Origin
Phylogeny
Dispersed
Flora
