Protoplast Fusion Of Non-Pathogenic Fusarium Oxysporum Strain Fo47 And Actinomyces PR And SG2

Fusarium wilt diseases of many crops can controlled by non-pathogenic Fusarium oxysporum Strain Fo47, which also can enhance the growth of crops. Protoplast fusion was used to improve the performance of Fo47, such as increasing the growth rate, the fungicide resistance,the ability to improve the growth of cotton and the control effect on fusarium wilt disease of cotton.The conditions to get the sensitive myceliums of strain PR and to inactivate the protoplast of strain PR were determined. The logarithmic phase of strain PR is 72～96h in MC medium on shaker at 28℃150 r/min. The optimal concentration of sucrose and glycin to train the maximum sensitive myceliums was 0.3g/mL and 5×10-3g/mL respectively. The enzyme with a concentration of 15μg/mL composed of lysozyme in 0.1g and snail enzyme in 0.05g was used to break the cell wall of PR in water bath at 35℃to make protoplast. The conditions to inactivate the protoplast of strain PR were 10min in water bath at 55℃and 5min under uviol lamp at 20cm.The protoplasts of parents were inactivated by heat and ultraviolet as genetic markers,protoplast fusion of inter-kingdom was conducted under among non-pathogenic Fusarium oxysporum Strain Fo47,endophytic actinomyces SG2 with the inhibition of growth of Fusarium oxysporum f. sp. niveum and hyperparasite strain PR with the inhibition of growth of Fusarium oxysporum f. sp.vasinfectum and high growing ability. 12 recombinants, F-1,F-2,F-3,F-4,F-5,F-6,F-7,F-8,F-9,F-10,F-11 and F-12, were obtained after protoplast fusion with PEG as fusogen.The growth rate and the resistance to Carbendazim of the recombinants were different on PDA. The growth rate of strain F-3,F-8,F-9,F-10 and F-12 was significantly faster than parent strain Fo47; The fungicide resistance of F-8,F-9,F-10,F-11 and F-12 increased obviously compare with strain Fo47, and the tolerance levels to Carbendazim of F-8,F-9,F-10 and F-12 were 3,9,6,6μg/mL respectively, higher than Fo47(2μg/mL).The recombinants could improve the growth of root, fresh weight and dry weight of cotton obviously. The enhancement of F-2,F-7,F-8 and F-9 to the growth of root were significantly better than strain Fo47(P=0.05). Strain F-4 and F-10 raised the fresh weight obviously,and F-10 had significant difference. The effect to increase the dryweight of cotton of F-4,F-5,F-8 and F-10 was better than Fo47.The control effect of the recombinants on fusarium wilt disease of cotton increased substantially. Especially the control effect of F-1,F-11 and F-12 reached 60.82%,70.1%,60.56% respectively.