Test method for inhibiting Phytophthora nicotianae

Abstract

The invention relates to a test method for inhibiting Phytophthora nicotianae. A plate dilution coating method is adopted to separate rhizosphere soil microorganisms of healthy tobacco plants in the tobacco field with the tobacco black shank disease, and two antagonistic bacteria and three Trichoderma spp. are screened out from Phytophthora nicotianae by a plate confrontation test; and the numberof two antagonistic bacteria is B1 and B2 respectively, and the single-bacterium bacteriostatic rates of both of the bacteria are more than 80 percent, wherein the inhibition rate of the B1 to Phytophthora nicotianae is more than 90 percent, and both of the bacteria are identified to be paenibacillus polymyxa; the number of the three Trichoderma strains are YCS-Tr1, YCS-Tr2 and YCS-Tr3 respectively, the single-bacterium bacteriostatic rates of the strains are more that 94%, and the three strains are identified as green Trichoderma spp., Trichoderma paraviridescens and Trichoderma koningiopsisrespectively. The test data analysis obtains the strain combination mode with the optimal bacteriostatic rate, is beneficial to more accurately implementing the prevention and treatment work of inhibiting the Phytophthora nicotianae in the later field application, and provides a reference test method for acquiring a composition for efficiently and stably inhibiting the Phytophthora nicotianae.

Description

technical field [0001] The invention relates to the field of tobacco planting, in particular to a test method for inhibiting Phytophthora tobacco. Background technique [0002] Tobacco black shank caused by Phytophthora infestans is the main root and stem disease of tobacco in my country. It first occurred in the Huanghuai tobacco-growing area. At present, it occurs to varying degrees in all major tobacco-producing areas. Among them, Anhui, Shandong, and Henan are the most serious diseases in history. Area. As the area of ​​continuous cropping tobacco fields continues to expand and the number of years of continuous cropping continues to increase, the prevalence of the disease is aggravated. According to incomplete statistics, the average annual economic loss caused by tobacco black shank in my country is more than 100 million yuan. At present, for the prevention and treatment of tobacco black shank disease in production, the compound preparations of metalaxyl mancozeb are m...

AI Technical Summary

Problems solved by technology

At present, for the prevention and treatment of tobacco black shank disease in production, the compound preparations of metalaxyl mancozeb are mainly used for prevention and control. Due to long-term, excessive or irregular drug use, the degradation products of metalaxyl and mancozeb have become the most common in my country. One of the main pesticide residues in tobacco leaves. At the same time, the resistance of pathogenic bacteria to this kind of drugs is also increasing, the efficacy of the drugs is reduced, and the problems of farmland micro-ecological imbalance and serious environmental pollution are becoming more and more prominent.

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