Optimization Of Cotton Ovules Culture In Vitro And The Expression Of Genes Relative To Synthesis And Transport Of Brown Pigment

Brown cotton whose fiber has natural color belongs to upland cotton,the color is the result of pigment deposition.Brown cotton can save production costs and reduce environmental pollution in the subsequent processing printing because of its fiber has natural color.But the defects of short lint,unstable pigmentation,uneven pigmentation and genetic instability restricte its production and application.In this experiment,we selected Zongcaixuan1 and Simian3 as materials,optimized cotton culture system in vitro,researched physiological and biochemical changes,gene expression changes at fiber development in vitro,to explore the regulation of pigment synthesis and accumulation of brown cotton in vitro.The main results of this test are as follows:1.The optimal conditions of cotton ovule culture in vitro: 1 days post anthesis ovule of brown cotton was more suitable for vitro culture;the suitable disinfection method wsa to use 75% ethyl alcohol for 10 minutes plus 0.1% corrosive sublimate for5 minutes;the suitable hormone and its concentration ratio was GA3 1.0 ?mol·L-1+ IAA1.0 ?mol·L-1+ZR 1.0 ?mol·L-1.2.Fresh weight and fiber length of white cotton ovules were greater than the brown cotton;brown cotton fibers in vitro were dyed blue by DMACA,and deeply stained,while white cotton ovules dyed lighter,significantly lower than the brown cotton.3.During the fiber development in vitro,the contents of total flavonoids,proanthocyanidins and catechin in brown cotton fiber were higher than those in white cotton,all showed first increased and then decreased.The content of total flavonoids peaked at 20 DAC in brown cotton fiber;The contents of soluble and insoluble proanthocyanidins peaked at 20DAC;The content of catechins peaked at 20 DAC in brown cotton fiber.4.The expression of pigment synthesis key enzyme gene(GhCHS,GhF3 H,GhDFR,GhANS,GhANR)in brown cotton fiber was significantly higher than in white cotton,and expressed highest at 10 DAC,then all showed a downward trend.The expression of GhTT12 showed a sharp rise in brown cotton and reached a significant level at 25 DAC.5.Compared with the dark treatment,the Light treatment significantly inhibited the expression of gene ANS,ANR,DFR,CHS,F3 H,TT12 at 15DAC;at 20 DAC,Lighttreatment inhibited the expression of gene ANS,ANR,DFR,CHS,F3 H,but promoted the expression of TT12.