二倍体栽培棉种草棉和亚洲棉的核型比较研究

Comparative Studies on Karyotypes of Cultivated Diploid Cotton Species Gossypium herbaceum and G.arboreum

以二倍体栽培棉种草棉(Gossypium herbaceumL.)3个品种和亚洲棉(G.arboreum L.)6个品种,以及1个亚洲棉与草棉种间杂种 F_1为材料,进行核型分析。结果表明,草棉和亚洲棉在核型上基本相似,其主要差异是草棉具有2对 st 染色体,而亚洲棉中没有;虽然2个棉种的核型类别都属于2A 型,但草棉的核型比亚洲棉更对称,属于较原始的类型。来自不同地区的6个亚洲棉品种的 sm 染色体数目分别为4个、6个或8个,随体染色体数目分别为2个或4个。而且它们的 sm染色体和随体染色体的位置也有所不同。这表明,同一栽培种内来源于不同生态地区的品种间在核型上可能存在一定的差异。

Karyotype analysis of cultivated diploid cotton species was conducted by using 3varieties of Gossypium herbaceum L.,6 varieties of G.arboreum L.and 1 interspecifichybrid F_1 between the two species.The result showed that the karyotype of G.herbaceum was fundamentally similar to that of G.arboreum.The main difference be-tween the two species was that G.herbaceum had 2 pairs of st-chromosomes that didnot exsit in G.arboreum.Althogh the karyotypes of both G.herbaceum and G.arboreum belonged to 2A type,the karyotype of G.herbaceum appeared to be moresymmetric than that of G.arboreum,and was therefore considered more original.In G.arboreum,the numbers of sm-chromosomes and SAT-chromosomes of 6 varieties fromvarious regions were 4,6 or 8 and 2 or 4 respectively.In addition,the positions of thesm-chromosomes and SAT-chromosomes were also different with different varieties.There indicated that there might be some difference in karyotype in varieties belongedto the same cultivated species but came from different ecological regions.