+The Study On Regeneration System Of Sunflower

In order to establish the high efficient regeneration system of the sunflower, we used the mean of an orthogonal design,and optimized the process of callus induction, differentiation and rooting by screening the optimum genotype, explant materials, hormone and cytokine concentration, and additives.at the same time, we studies the phenolic compounds to the influence of Browning, by determining the total phenol content and PPO activity of the sunflower regeneration process; In those basees, the different genotypes of sunflower anthers was used as explants we studied from anther split period, hormone ratio, antioxidant VC, sucrose concentration, AgNO₃ and so on ,making the research of sunflower anther culture callus induction organization, callus process of differentiation process, aim to lay the foundation of future sunflower anther culture and bioengineering breeding.The main results of this study are as follows:Hybrid sunflowers were easier to realize regeneration than selfing ones; The best explant was four days cotyledon; The optimum induction medium was MS +2.0 mg/L 6-benzyladenine (6-BA) +0.5 mg/L naphthaleneacetic acid (NAA) +1.0 mg/L kinetin (KT), the maximum rate of callus induction was 100%; The optimum differentiation medium was MS +0.2 mg/L 6-BA +0.5 mg/L NAA +0.3 mg/L KT +0.3 mg/L silver nitrate (AgNO₃) +0.2 g/L active carbon (AC), and the buds differentiation rate was up to 71%; The best rooting culture medium was 1/2 MS +0.6 mg/L indolebutyric acid (IBA), the highest rooting rate was 77%.The analysis of variance showed that genotype, explants growth time, different kinds and concentration of hormone, AC concentration had a significant effect on sunflower regeneration.In sunflower anther culture, the heterozygous genotype is superior homozygous genotype. The best selection time is in the single nucleus time for the small spore, this time the sunflower face plate periphery flower petal assumes the pale-green, and has not launched, the tubular flower has not cracked completely, thrum for white to faint yellow. The best hormone combination of callus induction was 2mg/LNAA+2mg/L6-BA+2mg/LKT, the best hormone combination of differentiation was 6-BA(2mg/L)+NAA(0.5mg/L)+KT(1mg/L); The high sucrose density could obviously enhance the the induction ability sunflower anther callus, 6% was the best sucrose density. 200mg/L VC increases can the active control brown production, 0.4mg/L AgNO₃ enhance the thrum to injury the organization inductivity, reduces the brown rate.Phenol content of the hybrid is lower than inbred. The total phenol content and PPO (polyphenoloxidase) activenes were different with the different periods of cotyledon, explants, the leaf blade, callus. When culturing time increase, the phenol material accumulateed unceasingly, brown also intensifies, regeneration activity reduced. The results indicates that the total polyphenol and PPO is an important factor in the development of Browning, add 200mg/L concentration of VC can inhibit the phenolic substances produced, effectively reduce Browning, improve regeneration rate, in explant based on the total phenols content and activity determination, PPO to alleviate Browning, have very great help to improve regeneration rate.