Font Size: a A A

Study On The Control Efficiency And Induced Resistance Of Bacillus Amyloliquefaciens B1619 Against Root Knot Nematode Disease Of Facility Vegetable

Posted on:2017-04-13Degree:MasterType:Thesis
Country:ChinaCandidate:P P JiangFull Text:PDF
GTID:2323330518479977Subject:Agricultural Extension
Abstract/Summary:PDF Full Text Request
Root knot nematode commonly occur in the facility vegetables,high yield,even for diversified planting layout cause harm shed indoor growing root knot nematode,causing varying degrees of damage,the light cut about 10%,by weight more than 60%sometimes even crops.Currently,control root knot nematode mainly depend on chemical control,however chemical nematicides are usually toxic,there are residues,environmental pollution and other issues,so biological control facility vegetable root knot nematode research are highly concerned about domestic and foreign experts in plant protection.The control effect of Bacillus amyloliquefaciens B1619 against root-knot nematode of facility vegetables was studied.And the toxic effect of B1619 against vegetables root-knot nematode was studied by the laboratory toxicity test.The results of experiments on the control of facility vegetables showed that:In general,the control effect of furrow application was higher than hole application.When the application amount of B1619 was less,the control efficiency of hole application was higher than furrow application.When the total amount of each plant was 16g,the effect of facility tomato and cucumber were 69.12%and 87.77%separately.Results of laboratory tests for toxicity showed that:the EC50 of isofenphos-methyl to J2 were 46.4240 mg/L(24 h)and 33.2889 mg/L(48 h);the EC50 of B1619 to J2 were 6.9×108 CFU/mL(24 h)and 5.7×108 CFU/mL(48 h);the EC50 of B1619 crude extract to J2 were diluted 5.1217 times(24 h)and 5.6922 times(48 h).The results of facility test and the laboratory virulence detennination showed that B1619 had obvious control efficiency on facility vegetables root-knot nematode.Previous studies showed that the biocontrol bacteria can stimulate plant induced disease resistance signal pathway and enhance the plant resistance to disease,induced resistance is one of the main mechanisms of plant disease resistance.In this paper discusses the expression levels of defense genes and the activity of antioxidant enzymes in tomato at different times induced by Bacillus amyloliquefaciens B1619.Analyzed the relative expression of PR1 and PAL2 at 0 h,8 h,24 h,48 h,96 h,and the activity of SOD,POD and CAT at 0 h,24 h,48 h,96 h,144 h,168 h,after inoculated with B1619 or/and nematodes.The results showed that the relative expression of defense genes and the activity of antioxidant enzymes were changed in tomato leaves after inoculated with B1619 and nematodes.The relative expression of PR1 was 6.0 times of CK respectively at 48 h;the relative expression of PAL2 was 3.3 times of CK at 144 h;SOD and CAT activity reached peaks at 24 h,which were 1.3 and 1.5 times of CK respectively;POD activity reached peak at 48 h,which was 1.3 times of CK.The results showed that B1619 could induce the expression of defense genes(PR1 and PAL2)and increase the excitation of antioxidant enzymes(SOD、POD and CAT)activity in tomato,and enhanced the ability of resistance to tomato pathogen infection.The biocontrol strain Bacillus amyloliquefaciens B1619 has good control effect on the root-knot nematode disease of facility vegetable.In this paper,the fermentation medium and the culture conditions of B1619 were optimized by single factor horizontal and orthogonal experiments to improve the fermentation efficiency of B1619.Results showed that the fermentation medium of three main factors of the optimum parameters were obtained:yeast extract 0.25%,soy flour 2.00%,auxin 0.05%,the fermentation efficiency of the optimized fermentation improved 21.79%compared with the initial medium.The best combination of fermentation conditions of three main factors were temperature 28 ℃ speed 180 r/min,installed fluid volume 60 mL/250 mL,and the fermentation efficiency of the optimized fermentation improved 35.42%compared with the initial culture conditions.Optimized biological fermentation process obtained bacteria 7.13×109 CFU/mL,which increased by 87.83%compared with the initial fermentation process(3.80×109 CFU/mL).
Keywords/Search Tags:Root knot nematode, Bacillus amyloliquefaciens B1619, Control efficiency, induced resistance, Orthogonal optimization
PDF Full Text Request
Related items