棉属野生种克劳茨基棉(Gossypium klotzschianum)基因组向陆地棉的渐渗

摘要

棉花远缘种质是改良栽培种的丰富资源,野生种遗传变异的有效利用依赖于鉴定并渐渗理想的野生种DNA进入栽培种的能力.为了检测二倍体野生种克劳茨基棉染色质在陆地棉中的渐渗情况,构建了一个来自于(陆地棉×克劳茨基棉)×陆地棉的BC1 F2群体,并用320个覆盖棉花基因组的SSR标记来监测外源种质的转入;只有38个标记在BC1F2群体中显示了分离,这些标记分布于14条染色体,组成了18个渐渗片段;通过比较发表的棉花遗传图谱,这18条渐渗片段的总长为595 cM;同时两个形态性状(黄色花瓣和开放花蕾)被定位于13号染色体.通过分子和形态鉴定,结果证实克劳茨基棉染色质已被渐渗进陆地棉遗传背景中.利用这种特异的标记将会促进理想的外源基因转入栽培棉.%Exotic Gossypium germplasms are rich sources of useful agronomic traits for improvement programs of cultivated cotton. Efficient use of genetic variation available in the wild relatives depends on the ability to identify and introgress desirable DNA segments from wild species into cultivated cotton. To introgress genes from G. klotzschianum into G. hirsutum, a BC1 F2 population from (G. hirsutum×G. klotzschianum) ×G. hirsutum was constructed. A total of 320 SSR primers covering the cotton genome were selected to monitor alien germplasm transmission. Only 38 markers showed segregation in the BC1 F2 population, and they were distributed in 14 different chromosomes and constituted 18 introgressed segments. The total length of the 18 introgressed segments was 595 cM based on a cotton consensus map. Two morphological traits (yellow petal and open bud)were mapped on chromosome 13. Our molecular and morphological identification confirmed the presence of G. klotzschianum chromatin in the BC1 F2 interspecific progenies. The use of species-specific molecular markers will greatly facilitate introgression of desirable alien genes into cultivated cotton.