杨柳科植物染色体数目及其进化的研究(英文)

A Study on the Chromosome Numbers and Their Evolution in Salicaceae

本文报道了8种3变种2杂交种杨树的染色体数目,结果均为2n=38,其中3种1杂交种为首次报道。统计了277种杨柳科植物的染色体数目,分析了其可能的进化途径,初步结论如下:(1)现代杨柳科植物是一群具有多个染色体基数、处在不同倍性水平的多倍体系列;(2)其次生基数X_2=19,11,12和14,这些次生基数可能是古多倍体起源的;(3)杨柳科植物染色体的原始基数可能是X=6;(4)现代杨属和钻天柳属植物染色体数目的进化处在同一水平上,即古多倍体水平上;而柳属中大约50％的种进化为次生多倍体,最高为16倍体。绘出了杨柳科植物染色体进化谱,讨论了该科植物染色体基数进化的可能途径。

Chromosome numbers of 8 species, 3 varieties and 2 hybrids of poplars were observed and 2n=38 were found for all specimens. Statistics of chromosome numbers support the following proposals: I.recent Salicaceae should be regarded as a group of plants with several basic chromosome numbers and at various ploidylevels; 2. the secondary basic numbers are x_2=19, 11, 12 and 14 and possibly originated from the archaic polyploids; 3.their original basic number might be x=6; 4 .the evolution of chromosome numbers in Populus and Chosenia may stay at the same level as that in archaic polyploids, but about 50% of Salix species evolved into secondary polyploids.