Preliminary Study On Screening And Mechanism Of Biocontrol Agents To Induce The Resistance To Rice Blast

Rice blast is one of the most serious diseases in rice production.In this paper,the rice blast fungus was used as a target,and the biocontrol strains that can infect rice blast resistance were screened out by microbial metabolite treatment and identified.A preliminary study of its mechanism of inducing resistance and inducing active substances,the specific findings are as follows.1.Screening of fungal or bacterial strains inducing rice blast disease resistance in Orza sotiva ssp.kengRice blast as a disease in need of prevention and control.The rice seeds are coated in the fermentation broth of 4800 strains of biocontrol strains and are put into the field for preliminary screening.The effective strains Snefw302,Snefw301,Snef1503,Snebw149,Sneb1236,Sneb1068 and Sneb16 are obtained.These 7 effective strains not only induce rice blast resistance,but also increase the yield of rice.7 effective strains screened in the field are screened indoors in constant temperature greenhouse.Finally,4 effective strains,Snefw301,Snef1503,Snebw149 and Sneb1236,which can induce rice blast resistance and growth promoting effect are obtained.Among them,Snefw301 had the highest control efficacy against rice blast and the control effect reached 55.2%.Snefw301 promote the growth of plant height and root length,the increase of dry weight and fresh weight.The results showed that Snefw301 could significantly promote the growth of rice seedlings.2.Identification of highly effective strainsOn the basis of morphological identification and physiological and biochemical identification,identification of the efficient strains of rice blast resistance,Snefw301,Snef1503,Snebw149,Sneb1236,was identified by molecular biology.Confirm its classification status,Snefw301 is Penicillium polonicum,Snef1503 is Penicillium crustosum,Snebw149 is Bacillus cereus,and Snebw149 is Serratia liquefaciens.3.Snefw301 induced resistance to rice blast disease related enzymesBy measuring the activity of resistance related enzymes in rice leaves,it was found that the effective strain Snefw301 was inoculated with rice blast and inoculated with rice blast after inoculation with rice blast.Compared with the inoculated blast fungus,the peroxidase(POD),superoxide dismutase(SOD),polyphenol oxidase(PPO)and phenylalanine lyase(PAL)in rice leaves Increased activity,and then increased the resistance of rice leaves to blast.These disease resistance related enzymes were involved in the process of Snefw301 inducing rice blast resistance.It may be one of the mechanisms of inducing rice blast resistance.