| Rice blast disease is an important disease of rice, seriously restricted the production anddevelopment of rice. According to the biological control of rice blast, the screening and identificationwas carried out of which antagonistic bacteria can be used to rice blast prevention. And study on therequirement of antagonistic bacteria nutritional factors, environmental factors, stability and its applied,and measured the effect of antagonistic bacteria fermentation broth of rice leaf disease enzyme activity,meanwhile we studied the effect of prevention and controlment of the rice blast in the field. The mainresults are as follows:The isolation, screening and identification of antagonistic bacteria. Through the rice plant and soilsamples around the roots of a large number of isolated strains, there are a large number of bacteria,fungi and actinomycetes strains, the soil samples from the rice field of Qigihar branch of HeilongjiangAcademy of Agricultural Sciences. Isolation and enumeration results show that, the number of coloniesof bacteria isolated from the plant surface was3.2×104cfu/g, actinomycete colony number was1.5×101cfu/g, fungal colony number was1.3×101cfu/g. Meanwhile, a screening test performed by the testresults showed that: The bacteriostatic circle appeared in different dishes, in which the bacterial isolateswere obtained in2strains of antibacterial ability,5strains of actinomycetes was obtained,2strains ofmolds. And biological identificate on the2strains of strong inhibition ability, the identification resultsshowed that the2strains belong to Bacillus subtilis.Antagonistic bacteria required nutritional factors, environmental factors and stability. With theantibacterial ability of the antagonistic bacteria number1as the research object, study the influence ofenvironmental factors, nutritional factors and stability required for their growth. The results showed thatthe strain in the culture of20h can achieve the maximum growth, and glucose, peptone as the suitablecarbon and nitrogen source. The strain of bacteria belonging to medium temperature, its oxygenrequirements in general, but the stability of its strong antimicrobial activity of the fermentation broth oftemperature, light and save time there was a certain stability.Effects of antagonistic bacteria fermenting liquid on the activity of key enzymes in leaves of ricedisease resistance. By foliar spray of fermentation liquid, confirmed the antagonistic bacteria can induceeffect on defense enzymes, in the application of the antagonistic bacteria fermentation liquid. The POD48h content of up to six times higher, and PPO12h is four times higher, PAL12h content is25%higherthan the control. To some extent the barrier effect of stress change, tests confirmed the trend of severalenzymes more consistent, spraying broth and inoculated treatment, increasing enzyme activity valuesoccurred earlier. While activity only increased the value of inoculation appeared later.Effect of antagonistic bacteria fermented liquid in the controling blast rice. Through Plotexperiment and investigation on the rice we found that Spraying broth to leaf blast and panicle blasthave some control efficiency effect. Fermented liquid treatment plant leaf blast once and twice theincidence and disease index were lower, on average of3.93percent,2.54and3.15percent,2.02, control incidence of6.9%, the disease index3.22, the control effect reached54%. August survey of PanicleBlast Disease incidence rate is below7.35%, the disease index was below5.10; September panicle blastincidence and disease index have risen, which handle twice panicle blast incidence and disease indexwere low,6.48%,5.23, control the incidence of15.65%,12.83disease index. Analysis of thedevelopment of the disease control, the control effect was77%. Antagonistic bacteria fermented liquidspraying once or twice can reduce the incidence of rice blast, played a very good protection, theprotection rate can reach nearly two-fold effect. |
PDF Full Text Request