Studies On The Development Characteristics Of Fiber Qulity And The Effect Of Growth Regulators On The Fiber In Nature-colored Cotton

This field experiment was coducted in the Experiment Station of Yangzhou University in 2006-2007 to investigate the development characteristics of fiber quality, the effect and physiological mechanism of growth regulators on the fiber in Nature-colored cotton. Two Nature-colored cotton cultivars were selected as experimental matrrials, which were XiangcaiNo2.(brown) and Wanmian39.(green), using Sumian No.9 (white) as the check . The main results were as follows:1, On the aspect of the development characteristics of fiber quality , the fiber length , strength, micronaire, maturity of the brown cotton were higher than the green one.In comparation to the check of Sumian No.9, the fiber development characteristics of Nature-colored cottons were different.(1)The fiber length of brown cotton was longer, the brown and the green cotton cultivars had lower the fiber elonging rate in the fastest development period, and the fiber length of the green cotton was shortest. (2)The fiber strength was lower for Nature-colored cottons and the key period of the strength development was during the fiber extension. (3) The fiber micronaire of Nature-colored cottons inceased faster during 0 to 30 DAF,but the increasing rate of the fiber micronaire were lower and that of the green one was lowest. (4)The fiber maturity was lower and the development period of the maturity was longer for Natrue-colored cottons. Compared to the white cotton cultivar, the fiber quility of Natrue-colored cottons were almost low, and the quality of the green cotton were lower than that of brown one.2, The fiber quility of Nature-colored cottons were inproved by spraying three growth regulors. (1) The fiber length of the brown and the green cotton were 31.46mm and 29.12 mm respectively by application of GA3, that of the white cotton was only 29.0 mm. Compared to the check, the fiber length of the colored cottons decreased with application of 6-BA and ABA. (2)Although the fiber strength was significantly increased with application of 6-BA, it was still lower than that of the white cotton.The fiber strength decreased with application of ABA, and there was no significant effect by application of GA3. (3) The fiber micronaire increased with spraying of 6-BA, ABA or GA3, and the effect of ABA was biggest. The fiber micronaires of the brown and the green cotton bolstered 4.62 and 4.82 respectively with application of ABA, that of white cotton was only 4.32. (4) The trend of the fiber maturity increase was coincident with the fiber micronaire by application of three regultors. The fiber maturity of the brown and the green cotton bolstered 1.82 and 1.77 with application of ABA, that of white cotton was only1.56.3, The application of the three growth regulators increased the physiology activities of the boll and it's oppsite leaf for the colored cottons. (1)The chlorophyll, soluble suger and sucrose content in the oppsite leaves enhanced. Photosynthetic rate was increased and exportation of the carbohydrates to the bolls were bolstered. (2)The boll volume and boll weight were increased, and the increase rate of boll shell's weight decreased. (3) The increase rates of soluble sugar and sucrose contents were decreased in boll shell and the exportation rate was enhanced.(4)The activity of ATP enzyme, the Sucrose Synthase and the UDPG–pyophosphorylase were enhanced in the fiber. (5) The fiber IAA contents at 10 and 20 DAF for the colored cottons were increased significantly with application of 6-BA, ABA and GA3. The fiber ABA contents for the colored cottons after flowering were also significantly increased by application of the three regulators. The fiber GA3 contents were increased at 10 and 40 DAF for the colored cottons with application of 6-BA and ABA, and the fiber ZR contents at 10 and 40 DAF for the colored cottons were increased either.There were significant positive correlation between the contents of IAA , GA3 in the fiber and the fiber length (r=0.9599,r=0.8584). There were also significant positive correlation between the fiber ABA content and fiber strength, fiber maturity respectively(r=9200,r=0.8955). The fiber ZR content were positive correlation significantly with the fiber maturity(r=0.8760) and negtive correlation significantly with the fiber length (r=-0.9259). The above results indicated that the growth substance adjusted the endogenous hormonal system of the boll, which enhanced the developing quality of the fiber and improved fiber quality of the whole plant for Nature-colored cotton.