Characteristics of Fiber Quality in Cotton Development and Its Regulation by Hormone in Two Natural Colored-Cotton Cultivars

Abstract

The brown cotton cultivar Xiangcaimian 2,green cotton cultivar Wanmian 39,and white fiber control cultivar Sumian 9 were used to study the fiber developmental characteristics and the effect of hormones on fiber quality with sampling different stages after anthesis.The results showed that fiber length of the brown and green cotton cultivar was lower than that of control,and that of the green cotton always lower than that of brown cotton.Compared with the control,the fiber strength,fiber micronaire,fiber maturation of natural-colored cotton were lower.The lower fiber length for the green cultivar was due to the less increase during 10 to 30 days post anthesis(DPA),the lower fiber strength,fiber micronaire,fiber maturation of natural-colored cotton were due to the slower growing speed at the pivotal stage.The IAA content at 10 DPA,the ABA content at 30 to 40 DPA in fiber of the two natural-colored cultivars were lower than that of Sumian 9.In comparison with control,in the treatment of applying 20 mg L-1 GA3,the IAA content in the fiber of Xiangcaimian 2 and Wanmian 39 at 20 DPA increased by 51.07% and 64.33%,respectively at boll opening stage,and fiber length also enhanced by 8.13% and 13.96%,respectively at boll open stage.The ABA content in fiber in the treatment applying 20 mg L-1 ABA at 40 DPA increased by 38.96% and 24.40% for Xiangcaimian 2 and Wanmian 39 respectively.The fiber strength,fiber micronaire,fiber maturation also enhanced at the boll opening stage,especially for Wanmian 39.Those results suggest that endogenous hormones affect fiber quality,application of ABA and GA3 with suitable concentration can increase the content of hormones in the natural-colored cotton fiber and advance the fiber quality,and the effect of different hormones are different.