Preliminarily Study On Induction Culture And Browing Reaction Mechanism Of Carya Cathayensis Sarg

In this study, researching on the tissue culture of Carya cathayensis Sarg. by the follow methods,such as selective medium,sterilization methods and anti-browning program.And combined with the explants biochemical markers and cell slice observation to study of the tissue culture and browning mechanism of Carya cathayensis Sarg. And provided a theoretical basis for accelerated Carya cathayensis Sarg. breeding, improved the varieties of seedlings.The results are as follows.(1)In the selection of the best explants, stems with buds was the best explants, it can generate callus and the bud also germination, the average rate of callus was86.43%, the average rate of sprouting is45.29%.(2)The optium medium was WPM,The average browning rate of WPM was40.35%, and the average germination rate was45.34%.(3)The best method of sterilization was to soak the explants in1000times of carbendazim for30mins,75%alcohol for60s,0.1%mercuric chloride for10mins.In this method,the average rate of contamination was26.21%, the average rate of germination was44.91%.(4)The best method of sterilization was put200mg/L penicillin sodium into the medium, the average rate of germination was7.80%.(5)After the anti-oxidant added into the medium, Vc100mg/L+Na2S2O30.2mg/L+AgNO30.10mg/L+PVP0.1mg/L has a good effect of anti-browing,the germination rates was22.23%,and the average rate of germination was43.80%.(6)Nature anti-oxidant has a good effevt of anti-browing.After added3.0g/L of tea into the medium,the average browning rate was31.59%.And the average rate of germination was46.23%.(7)3.0g/L tea with0.10g/L AgNO3has a good effect of anti-browing.,the average browning rate was23.07%.The average germination rate was45.47%.(8)In the selection of dark and cold culture environment,2days of10℃dark culture has an effect of anti-browning,the average browning rate was21.24%,the average germination rate was46.07%.(9)The optimal auxin types was2.4-D0.50mg/L+IBA0.20mg/L+6-BA0.05mg/L+KT1.00mg/L, the average rate of cure was94.38%, and the average rate of germination was46.46%.(10)4biochemical index of explants display that, the PPO activity of explants has gradually increased.PPO activity was significantly higher than the not browning explants. POD activity of the2explants showed a "convex" shaped curve.The content of MDA showed an upward trend. SOD activity and MDA content varies inversely. SOD activity gradually decreased with time in culture. (11)The cell sections shows that,with the incubation time increased and the the browning degree deepening,the colour of cell slice coloring deepen,and the cell gap became black.The brown material may related to the activity of PPO and POD.