| Lotus(Nelumbo nucifera)is planted in China widely.The lotus rot,caused by the Fusarium spp.,is one of the most serious diseases on lotus,which caused a series of serious loss on lotus’yield.The pathogen species of lotus rot are multifarious,Fusarium spp.is the primary pathogen.At present,the mainly method to prevent and control lotus rot is to use chemical fungicide,as the people pay more attention to food quality and safety,seeking a kind of green biological control method to prevent and control of lotus rot is imperative.Bacillus is used for bio-control bacterium commonly,which has highly antibacterial activity and has been used in preventing and controlling of plant diseases and insect pests,show a higher disease control effect.Bacillus is a common endophytes,which can stably colonize in plants by inoculating,so we can prevent and control plant diseases by inoculating Bacillus.This paper studied the distribution of bacillus in the lotus,tested the efficiency and the growth promoting effect of B-36 at different inoculation methods and quantities.At the same time we have tested the effect of colonization of B-36 at different inoculation methods and quantities.1.In accordance with Koch’s postulates,we have isolated two strains of pathogenic Fusarium F37、F-8.According to the cultural and morphological characteristics,the F37was identified as Fusarium equiseti and F-8 was identified as Fusarium oxysporum.To our knowledge,Fusarium oxysporum is a common pathogen that causes lotus rot and the report of rot disease caused by F.equiseti on Lotus is unusual in China.2.Bacillus has been separated from many organizations of lotus,and the separate frequency of different tissue is different.In the leaves,roots and petioles,the sum of the frequency is 82.27%,while in the seeds is only 1.27%.The inhibit growth rate reach90.46%at the concentration of 20%of B-36 sterilized broth filtrates and the VOC`s inhibit growth less than 20%.According to the colony morphological and the gyr A gene,B-36 was identified as Bacillus amyloliquefaciens.3.We tested the efficiency of B-36 at different inoculation methods and quantities on lotus rot and fond that the 800μL/plant control efficiency was 53.52%and the preventive efficiency was 43.51%.This result presents the longer effect advantage of biological control.There is no obvious change between spray and low doses processing,and all lower than the positive control.Bacillus B-36 can promote lotus`s petiole height,petioles diameter,leaf proportion obviously and some indexes reach significant difference.4.Bacillus B-36 can stable colonize in the lotus.We tested the effect of colonization of B-36~Rat different inoculation methods and quantities and fond that B-36~Rcan stable colonize in the petiole,leaf and stem of lotus,the population density of B-36~Rreached 10~2CFU/g-10~3CFU/g levels. |
