Biocontrol Of Bacillus AMCC100150 On Meloidogyne Incognita In Tomato

Plant-parasitic nematodes are one of the most important plant diseases in a variety of crops,resulting in a loss of about 157 billion dollars in production a year.With the technology development and the environmental awareness enhancement,more and more people pay attention to biological control methods.In this study,we obtained the purebred Meloidogyne incognita through the incubation.Based on the effects of different culture medium on the J2and the effects of Bacillus AMCC1500150 on the J2.The soil insect density and the dosage of biocontrol bacteria were determined in pot experiments.Finally,the control effect of Bacillus AMCC100150 on Meloidogyne incognita was verified by laboratory and outdoor pot experiments.And the main results were as follows:(1)Meloidogyne incognita obtained.Picking the Meloidogyne incognita oocysts on diseased tomato plants,and incubated through the Behrman funnel method.A large number of highly active and highly infectious J2 were obtained,as well as the soil with different insect density.It provides experimental materials for the later experiment.(2)Effect of medium on J2 survival showed,LB medium had little effect on the survival of J2,and the lethality rates in 12h and 24h were 2.52%and 4.93%.Thus,LB medium was selected as the fermentation medium.(3)Effect of Bacillus AMCC1500150 on J2 survival.In the in vitro test,the mortality of J2reached 83.6%and 100%after treated with the 48h fermented supernatant fluid for 24h and48h.The compounds with the antagonistic activity were resistanted to some extent against pH,temperature.(4)Insect density determination test showed,the tomato root-knot index was as high as 0.9of planting tomatoes in the soil with the densities of nematodes of 20 ind·g~-11 soil after 45days.With the increase of the densities of nematodes in soil,the root disease of tomato increased.(5)The colonization experiments showed that Bacillus AMCC100150 can survive stability in sterilized soil.Within 60 days,the strain concentration changed in the range of 10~6-10~7cfu·g~-11 soil.(6)Dose test of Bacillus AMCC100150 showed,the concentration of bacteria in the soil was 10~7 cfu·g~-11 soil,which had a good effect on the control of root-knot nematodes.(7)The results of laboratory and outdoor pot experiments showed that Bacillus AMCC100150 had a protective effect on root-knot nematode disease.Early treatment of Meloidogyne incognita disease for 7 days with the strain,which could effectively reduce the infection and harm of root-knot nematode on tomato root,and the control effect were 60.24%and 63.33%respectively.In summary,Bacillus AMCC100150 has good control effect on Meloidogyne incognita,and has good application value and promotion potential.