Abstract: By way of crossing the different species in gossypium and doubling the number of chro-mosomes, the new germplasms of tow types of ( G. hirsutum ?G. thurberi ) and ( G. hirsutum X G. arboreum ) were obtained by crossing shiduan 5 and G. thurberi , xingtai 6871 and wuanzhongmian. These materials were designated as "Shise" and "ZhangLu" respectively. The utilization value and the utilization opportunity of main economic characters in these hybrids and their progeny were studied, and the hybrids were backcrossed with various cultivars of the good comprehensive characters, yield characters, fibre quality and disease resistance. Then the composite hybridization of backcross progeny was carryed on by way of continual and directional selection. A new interspecific hybrid "Jimian 25" was developed. It possessed high and perma-nend yield, good fibre quality, and good disease resistance. Its mean prefrost lint yields in 1994 and 1995 were 23. 3% and 19.5% higher than those of control "Zhongmiansuo 12" respectively, as shown in the cotton regional and productive test for Hebei province. Its mean prefrost lint yields were 7.9% and 8. 5% higher than those of control "Zhongmiansuo 12" respectively, as shown in the cotton regional and productive test for the Yellow River Valley in 1995 and 1997. Its disease indexes of the fusarium and verticillium wilt of cotton were 17. 3 and 16.4 respectively. The fibre quality accorded with the demands of textile industry.

Key words: Cotton, Interspecific crossing, Jimian 25, Variety, Breeding

CLC Number: 

• S562