低温生防菌株的诱变选育及生防效果

为了提高生防菌株wswshg-10低温生长速度和抑菌活性,采用常压室温等离子体诱变技术(ARTP)对其进行诱变选育。结果表明,最佳照射时间为120 s,此时菌株致死率为95.4%,单菌落变大的突变率为24.5%。经低温平板培养和抑菌活性测定,从19个大菌落的菌株中筛选出2株低温生长速度和抑菌活性明显高于出发菌株的突变菌株WM4和WM7,其低温(15℃)生长速度分别是出发菌株的1.94倍和2.09倍,平板抑菌活性分别较出发菌株高26.2%和29.8%。传代培养10代,2株突变菌株在低温生长速度和抑菌活性方面均表现出良好的遗传稳定性。突变菌株WM7对玉米茎基腐病的温室防效为70.8%,比出发菌株高15.1%。本研究结果为适于低温地区生物农药的研发提供了菌株资源。

Mutation Breeding of Low-temperature Adapting Antagonistic Bacterium and Its Biocontrol Efficacy

In order to increase the growth rate of strain wswshg-10 at low temperature and inhibitory activity to pathogens,atmospheric and room temperature plasma (ARTP) was applied for the screening of mutants.The results showed that the optimal irradiation time was 120s,at which the lethal rate was 95.4％ and the large colony mutation rate was 24.5％.Two positive mutants WM4 and WM7 with rapid growth rate at low temperature and high inhibitory activity to pathogens were selected from 19 mutants by plate culture and dual culture methods.The growth rate of mutants WM4 and WM7 at 15 ℃ was 1.94 and 2.09 times the original strain and the inhibitory activity to pathogens was 26.2％ and 29.8％ higher than that of the original strain,respectively.Furthermore,strain WM4 and WM7 exhibited excellent genetic stability in terms of growth rate at low temperature and inhibitory activity to pathogens after 10 reproduction.Strain WM7 showed 70.8％ control effect on maize basal stalk rot in greenhouse test,which was 15.1％ higher than that of the original strain.This study will provide the potential strain to develop biocontrol agent for use in cold area.