青藏高原长花马先蒿的细胞地理学研究

Cytogeographical study on Pedicularis longiflora from the Qinghai-Tibetan Plateau,China

关键词:  长花马先蒿  青藏高原  染色体数目  起源中心  分化中心

Key words:  Pedicularis longiflora  Qinghai-Tibetan Plateau  chromosome number  origin centre  differentiation centre

摘要:

对青藏高原长花马先蒿9个居群的核型及细胞地理学进行研究,所有居群的染色体数目均为2n=16,染色体基数为x=8。现有的细胞学资料表明:分布于云南中甸的居群可能为较原始的类群,而分布于西藏日土和青海门源的居群较为进化。长花马先蒿的9个居群均为二倍体,并未出现多倍化现象,可能是由于在末次冰期青藏高原存在广泛的避难所,二倍体得到很好的保存,冰期对它们的影响不是很大; 也可能是对环境的选择压力造成的。

Abstract:

Karyotypes and cytogeography of 9 populations of Pedicularis longiflora from the Qinghai-Tibetan Plateau,China,were presented. The chromosome numbers of all populations were 2n=16,the basic chromosome number was x=8. The available chromosomal data indicated that the population from Zhongdian in Yunnan might be original,and the populations from Ritu in Tibet and Menyuan in Qinghai were advanced. 9 populations of P. longiflora were all diploid,without the occurrence of polyploidy. The one possible explanation is that Qinghai-Tibetan Plateau could have served as refuge during the last Quaternary glaciation,diploid is well preserved,and has been little effected by glaciation; the other possible explanation is that it may be effected by environmental selection pressure.