陆地棉和野生斯特提棉种间异源六倍体的合成与性状鉴定

陆地棉(Gossypiumhirsutum)是世界上重要的栽培棉种,野生斯特提棉(G.sturtianum)含有陆地棉所缺乏的许多优质基因。本研究通过陆地棉和斯特提棉的远缘杂交和染色体加倍,获得了自交可育的后代植株,对其进行流式细胞倍性检测和花粉母细胞减数分裂观察,筛选出2株染色体组完整的异源六倍体植株。统计鉴定表明,六倍体和亲本及三倍体比较,叶形介于双亲之间,叶面积增大,保卫细胞中叶绿体数明显增多;远缘杂种与亲本在花的表型性状方面差异明显,六倍体的花粉粒直径大于亲本和三倍体;六倍体棉纤维为白色,长度小于母本陆地棉,父本斯特提棉的种子腺体延缓发育性状在异源六倍体中得到表达。这些结果证明通过远缘杂交和加倍成功获得了陆地棉与斯特提棉间可育的异源六倍体新种质,为棉花遗传育种研究提供了有价值的材料。

Allohexaploid synthesis and its characteristic identification between cotton species Gossypium hirsutum and G. sturtianum

Gossypium hirsutum is an important cultivated cotton species and G. sturtianum is a wild cotton species with many excellent characteristics. In this study, we obtained fertile offsprings by interspecific distant hybridization and chromosome doubling between G. hirsutum and G. sturtianum. Through flow cytometry and meiosis observation of pollen mother cells, two heterohexaploid plants with complete chromosomes were selected. Further, the characteristic identification of their leaves, flowers and seeds was carried out, showing that the leaf shape of hexaploid was between their parents with increased leaf area, and the number of chloroplasts in guard cells obviously more than that of their parents and triploid. The flowers were significantly different between distant hybrids and their parents, and the pollen grain diameter of hexaploid was larger than that of parents and triploid. The fiber color of hexaploid was white, and the fiber length was shorter than that of G. hirsutum, and the traits of delayed seed gland development coming from G. sturtianum were expressed in the allohexaploid hybrids. These results of synthesized new fertile allohexaploid germplasms between G. hirsutum and G. sturtianum provide new valuable materials for the study of cotton genetics and breeding.