The Study Of Bacillus Methylotrophilus Lw-6 Against Botrytis Cinerea

Gray mold is a fungus diseases caused by Botrytis cinerea,wild and protected area are very common to find this diseases.It's difficult to prevent and easy to infect,caused the annual output loss is as high as 20%~50%,which is very threatening to production.In recent years,the disease has been widespread in all parts of the country,and has been increasing year by year.It has become one of the main limiting factors in cultivation which on the protected areas.Earlier,a strain Lw-6 which has significant resistance to a variety of pathogenic fungi was isolated by our laboratory from the rhizosphere soil of healthy tobacco plants in high incidence massif of Shaanxi.Combined with previous studies on Bacillus methylotrophicus Lw-6,the antagonistic effect of Lw-6 on Botrytis cinerea was studied with Lw-6 as the starting point in this study.We has studied the inhibition of spores germination of Botrytis cinerea by Lw-6 through the method of hanging drop.And the inhibition rate of the fermentation liquor can reach 93.87%.So it indicated that Lw-6 has a strong inhibitory effect on the Botrytis cinerea spores germination.On the other hand,the antagonistic plate method was used to detect the inhibitory effect of Lw-6 on the mycelia of Botrytis cinerea,with a bacteriostatic rate of 76.39%.Further studies showed that Lw-6 dilution had a certain furtherance to the germination of tomato seeds.When the concentration was 1×102mg/L,the radicle hypocotyl of tomato seeds increased significantly,which was 37.78% higher than that of the control group.In greenhouse experiments,we has tested the protective effect and therapeutic effect of Lw-6 on Botrytis cinerea with carbendazim as the control chemical.The results showed that Lw-6 was effective in the treatment and protection of Botrytis cinerea.And the control effect is more than 72% when the concentration is 2000mg/L.Moreover,the control effect of Lw-6 inoculant on tomato gray mold is slightly better than tobacco gray mold.In the field experiment,the drug concentration was selected as 2000mg/L according to the results of greenhouse experiment.The control effect of Lw-6 after three applications was 76.30%,and the control effect of carbendazim was 83.02%.It showed that the Lw-6 bactericide had a good effect on the control of tomato gray mould.