四倍体栽培棉与索马里棉异源五倍体杂种的细胞遗传学研究  

The Cytogenetic Studies on Allopen-taploid Hybrid between Tetraploid Cultivated Cotton and Gossypium So-malense

作　　者：李颖[1] 何鉴星[1] 张欣雪[1] 

机构地区：[1]中国科学院遗传与发育研究所,北京100101

出　　处：《棉花学报》2003年第4期195-200,共6页Cotton Science

基　　金：国家自然科学基金(30070482;30170560);863项目(2001AA2410813)资助

摘　　要：花粉母细胞(PMC)压片观察{[陆地棉(G.hirsutum L)×索马里棉(G.somalense Grke)]×海岛棉(G.barbadense)}的三元杂种及[(陆地棉×索马里棉)×陆地棉]的二元杂种中期Ⅰ染色体构型,这两个杂种都是异源五倍体(2n=5x=65),比较了两个杂种形成的多价体、二价体及单价体的频率。三元杂种具有多价体的PMC占22.03％,具有棒状二价体的PMC占57.29％,而二元杂种分别为8.33％和31.74％。三元杂种形成异源多价体和棒状二价体的频率比二元杂种高一倍。以上结果暗示在三交种的异源五倍体减数分裂中,存在同源染色体与部分同源染色体竞争联会现象,进而增加了异源易位的频率,有利于E_2染色体组基因渐渗到AD染色体组。Chromosome configuration at M Ⅰ in PMC meiosis between trispecific hybrid [( G. hirsutum L×G. somalense Gilrke ) ×G. bardadense ] and backcrossed hybrid [( G. hirsutum × G. somalense Gilrke) × G. hirsutum] were studied. The two hybrids were allopenta-ploid(2n=5x=65). And the frequency of multi-valent, bivalent and univalent were made a comparison between the two hybrids. There was 22.03% PMC with multivalent and 57. 29% PMC with bar bivalent in the trispecific hybrid, while there was only 8. 33% and 31. 74% respectively in the backcrossed hybrid. The frequency of multivalent and bar bivalent in the trispecific hybrid was twice as that in the backcrossed hybrid. Those results inferred that there was competitive allosyndetic pairing between homologue and partly homologue. Therefore, it is possible for the trispecific hybrid to accelerate gene intro-gression from E2 chromosome into the (AD) genome and to increase the frequency of chromosome translocation between E2 and (AD) genome.

关 键 词：四倍体栽培棉 索马里棉 异源五倍体 杂种 细胞遗传学 染色体构型 陆地棉 海岛棉 减数分裂 竞争联会现象 异源易位 

分 类 号：S562[农业科学—作物学]