In this paper,chromosome numbers and karyotypes were reported for 21 populations of 13 species (including one variety) in the genus Allium L. The results showed that: basic chromosome numbers were 7, 8, and 11, and polyploidy was common in the species investigated;and 2A,2B,3A types were found according to Stebbins' karyotype classification.Three points were examined:firstly,the karyotype differentiation and evolution mechanisms of some populations in Sect. Rhizirdium G. Don; secondly, the cytogeography of A. sikkimense Baker and A. wallichii Kunth;and thirdly, the polymorphism of B-chromosomes and their significant roles in adapting to their habitats. In addition, based on our results and combined with previous cytotaxonomic studies,we suggested the karyotype evolutionary trends in Allium as:(1) The original basic chromosome number of the genus Allium is 8, and the other basic chromosome numbers evolved from the basic number 8. (2) There are two routes in the karyotype evolution of the genus Allium:one is 2A→2B→2C,which is the trend of karyotype evolution in populations with the basic chromosome number 7,while another trend in the populations with basic number 8 is 1A→2A→2B→2C. (3) Polyploidy seems to be one of the important evolutionary mechanisms for the genus Allium.%采用常规压片法,对13种(含1变种)21居群葱属(Allium L.)植物进行了细胞分类学研究.结果表明:所研究类群的染色体基数为7、8和11,核型的类型为2A、2B和3A型,并且存在2倍体、3倍体和4倍体.主要讨论了葱属根茎组(Sect.Rhizirdium G.Don)部分类群的核型分化和进化机制,高山韭(A.sikkimense Baker)和多星韭(A.wallichii Kunth)的细胞地理学,以及B染色体的多态性及其在生境上的适应意义.最后在本研究的基础上,结合前人的细胞分类学研究结果,对葱属植物的核型进化形成了如下认识:(1)该属植物的原始染色体基数为8,其他基数的类群是由基数为8的类群进化而来的;(2)葱属植物在核型类型的进化上存在两条路线:基数为7的类群核型进化趋势为2A→2B→2C,而基数为8的类群的核型进化趋势为1A→2A→2B→2C;(3)多倍化是葱属植物进化的重要机制之一.
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