甘肃风毛菊属植物区系地理研究及与邻近地区区系的关系

Floristic study on the genus Saussurea in Gansu and floristic relations with its adjacent regions

关键词:  甘肃  风毛菊属  区系特征

Key words:  Gansu  Saussurea  floristic characteristic

摘要:

根据对风毛菊属植物野外调查,标本的收集、整理和系统鉴定,该地区风毛菊属植物共有57种1变种,隶属于4亚属,在甘肃省有2个分布丰富区:青藏高原东、北缘的甘南地区和祁连山地。分析表明,风毛菊属植物是一个北温带分布的属,可划为5个分布型和2个变型,其中以中国特有、横断山脉—喜马拉雅分布最多(分别占36%和29.5%),特有属为新特有属,说明该区系属于一个年轻的、以横断山脉—喜马拉雅分布为主的温带性质,并与青藏高原、中亚地区有密切联系; 喜马拉雅、横断山区是风毛菊属植物的现代分布中心和分化中心,华北、华中地区是一个次生分布中心; 菊科在古地中海地区于第三纪的早、中期得到分化与发展,其中原始的帚木菊族向西南亚迁移时分化、衍生出原始的菜蓟族的祖先种,该族在大约第三纪从起源中心向中亚干旱地区分化出风毛菊属植物,因此,该区系起源于第三纪的中亚至喜马拉雅一带; 青藏高原的隆起、海浸海退,使属内种类剧烈分化,第三纪、第四纪北半球冰期、间冰期交替作用,使本区系向亚洲温暖地区迁移,并进一步发展,形成了现今的区系成分。

Abstract:

Saussurea is with about 400 species from Compositae in the world and about 264 species in China and 57 species and 1 variety that belong to 4 subgenera in South Gansu and Qilianshan(east and north edge of Qinghai-Tibet Plateau). Saussurea is a genus of North Temperate distribution. The floristic characteristic indicates that on the level of species,the areal type of Saussurea is dominated with endemic to China(36%)and Sino-Himalaya(29.5%). It shows that the Temperate Zone with the areal type of Hengduan-Himalaya is a decisive factor of the floristic characteristics. Many species of Saussurea are young,local endemic species. Hengduan-Himalaya is both the centre of abundance and the centre of diversity in the genus,C.China region is a secondary centre of abundance. Since the early Tertiary period,the ancestors of Trib.Cynareae of Compositae migrated and differentiated though the Mediterranea,C.Asia into China,formed the ancestors of Saussurea. The region C.Asia-Himalaya is possible location of its origin,the ancestral primitive Saussurea might be originated at Tertiary period. The lift of Qinghai-Tibet Plateau played an important role in the differentiation of Saussurea,subgen.Eriocoryne,subgen.Amphilaena developed highly and the distribution to temperate Asia in this period,forming this young and distribution patterns of the flora now.