Fiber Color Change Research Of Colored Cotton Based On Ovule Culture In Vitro

Natural color cotton is one kind of desirable green, enviroment protection and healthy fabrics. In this paper, through the study the effects of osmotic regulators, plant growth regulators, flavonoids biosynthesis precursors, flavonoids metabolic inhibitors and ovule subculture on the in vitro fiber growth and color by ovule culture of color cotton, the optimize ovule culture system of brown cotton and green cotton will established. This research will lay a theory base and technique for cloning and identifying the fiber color related genes efficiently and further improving the fiber quality, fiber yield and fibeer color synchronously.Brown cotton lines Z1-61 and Z263, green cotton lines CC28 and G88,the white cotton line-RT-White(control sample) were used as plant materials, and the ovules of 3DPA were used for ovule culture in vitro. The basic medium was BT medium with the addition of10.0μmol·L-1IAA and 5.0μmol·L-1GA3, Based on this medium, different concentrations of osmotic regulators(mannitol, Na Cl, KCl, sucrose and Cu SO4), plant growth regulators and its inhibitors(Me JA and SHAM,BR and BRz, ABA and FLD, ETH and Co Cl2), protein synthesis promotor(Urea)and plastid protein synthesis inhibitor(chloramphenicol), flavonoids biosynthesis precursors(Phe, FA, PC)and flavonoids metabolic inhibitors were added to the basic medium separately as different treatment.After being cultured in vitro for 30 days, the fiber color, fiber length, ovule fresh weight, ovule dry weight and fiber dry weight of the five materials were determined, and multiple comparisons were carried out using least significant difference(LSD) or shortest significant ranges(SSR).The results are are as follows:(1)The pigmentation was observed until 15 d after ovule culture in vitro. Furthermore, 30g·L-1 mannitol, 0.1 mol·L-1 Na Cl, 0.20 mol·L-1 KCl, 10 g·L-1 sucrose, 40 μmol·L-1 Methyl Jasmonate, 5g·L-1 Urea, 1mg·L-1 Chloramphenicol or 0.10 mmol·L-1 phenylalanine were easily conducive to the pigment accumulation of brown cotton fiber. Among them the best treatment was 40 μmol·L-1 Me JA.(2)5 g·L-1 sucrose,0.05 μmol·L-1 Me JA, 0.5 μmol·L-1BR or 25μmol·L-1FA were suitable for fiber elongation of color cotton.(3)Under higher concentration of Urea and Chloramphenicol, the fiber color would weaken, fiber length and ovule fresh weight would decreased.(4)The ovule development and fiber pigment synthesis of brown cotton were affected with the application of flavonoids metabolic inhibitors,which could also affect ovule development and fiber elongation of green cotton.(5)There was genotype differences on in vitro fiber development. Green fiber cotton growth better than that of brown one.(6)However, the growth substances used in this experiment did not cause any significant change in the pigment of green cotton.(7)The color of brown and green fiber deepened obviously through successive transfer culture. These research optimized the ovule culture system for brown and green cotton, and finally medium prescription for increasing fiber color, fiber length and fiber dry weight were acquired.We draw the following conclusions:Sucrose provided the sugar source and osmotic environment for color cotton ovule growth and fiber development, and the appropriate concentrations of Me JA, BR or ferulic acid benefited the fiber elongation. There was a cross-effect between BR andMe JA. BR was mainly involved in fiber elongation, while Me JA may be involved in the pigment accumulation of brown cotton. Furthermore, certain concentrations of mannitol, Na Cl, KCl, sucrose,Me JA or phenylalanine were advantageous to the brown cotton fiber pigment synthesis. Fiber pigment synthesis is related to plastid protein metabolism. Flavonoids metabolism is not only related to fiber pigment synthesis, may also affect the color cotton ovule development and fiber elongation.However,neither osmotic regulators, plant growth regulators nor flavonoids biosynthesis precursors caused any significant change to the pigment accumulation of green cotton.Furthermore ovule successive transfer culture could provide better growth conditions for the color cotton ovule development and fiber pigment synthesis.