Abstract: With the global climate changing in recent years, the frequent occurrence of extreme high temperature climate has brought a great impact on the production of cotton. In order to understand the high temperature adaptability of iaaM transgenic cotton germplasm, with standard upland cotton lines TM-1, iaaM transgenic germplasm IF11 and its same genetic background germplasm IF11_(no) as materials, the difference of boll yield traits, fiber quality and cotton kernel nutritional quality of 3 cotton germplasms between 2012 (with relatively normal temperature in bolling stage) and 2013(with extreme high temperature conditions in bolling stage) were analyzed to explore the impact of extreme high temperature on the yield and quality of cotton. The results showed that the boll weight, seed index and kernel index, fiber length, fiber strength and micronaire grade decreased, the gossypol content of cottonseed kernel reduced, unsaturated fatty acids decreased, while the changes of protein and crude fat content were different among 3 germplasms under the extreme high temperature conditions in bolling period. Among 3 germplasms, the boll yield traits of iaaM transgenic germplasm IF11 decreased greatly but fiber quality was relatively stable, the kernel protein content of IF11 decreased slightly, crude fat content increased significantly, and gossypol content decreased the most under the condition of extremely high temperature at the cotton bolling stage.

Key words: cotton, bolling stage, extreme high temperature, boll yield traits, fiber quality, kernel nutritional quality