Biological prevention and control technology for rice blast

Abstract

The invention discloses a biological prevention and control technology for rice blast, and relates to the technical field of biological prevention and control of rice diseases and pests. The preparation method includes the steps of preparing a gradient diluent, preparing an NA solid culture medium, separating bacilli, preparing a PDA culture medium, preparing a spore solution, preparing extracts of murraya paniculata leaves and planting the rice. The bacilli separated according to the method can secrete antibiotic substances to prohibit growth of pathogenic bacteria and entice a plant defencesystem to resist invasion of pathogenic bacteria, and supplied testing bacterial strains can achieve an obvious prohibition effect on germination of mitogenetic spores, extension of germ tubes and formation of appressorium of the rice blast bacteria. The active substances in the bacterial strains have a great prohibition effect on the rice blast bacteria, and the prohibition rate to the mycelial growth of the rice blast bacteria reaches 80% or above. The extracts of the murraya paniculata leaves have a capability of resisting the pathogenic bacteria, insect antifeedant activity and a certain prohibition effect on the rice blast pathogenic bacteria, wherein the callus extracts have excellent bacteriostatic activity, and the bacteriostatic activity to the rice blast bacteria reaches 90% or above.

Description

technical field [0001] The invention relates to the technical field of biological control of rice diseases and insect pests, in particular to a biological control technology of rice blast. Background technique [0002] Rice is China's largest grain crop, and its output accounts for about 40% of China's grain output. The three major diseases of rice include rice blast, bacterial blight and rice sheath blight. Among them, rice blast is one of the most threatening diseases in rice production. It is caused by the fungus Pyrospora fungus and can occur throughout the rice development period. Due to the rapid prevalence of the disease, under suitable environmental conditions, it can cause a pandemic in a short period of time and bring huge losses to rice production. At present, in agriculture, disease-resistant breeding and chemical agents are mainly used to gradually control rice blast. However, due to the complex genetic background of Magnaporthe grisea, it is easy to mutate, a...

AI Technical Summary

Problems solved by technology

However, due to the complex genetic background of the rice blast fungus, it is easy to mutate, and it is difficult for the disease-resistant varieties to keep up with the variation speed of the physiological races of the pathogenic bacteria, which often leads to the loss of resistance of a new disease-resistant rice variety after a few years of planting.

However, chemical control will not only pollute the environment, reduce the quality of rice, and destroy the ecology, but also lead to the continuous increase of drug resistance of bacteria and reduce the control effect.