铜绿假单胞菌结合生物熏蒸防控辣椒疫病的效果

Integration of Pseudomonas aeruginosa with biofumigation to control phytophthora blight of pepper

为找到防治由疫霉菌(Phytophthora capsici)引起的辣椒疫病的有效方法,首先研究了生物熏蒸过程中土壤微生物数量变化。结果发现在生物熏蒸第7 d时,土壤疫霉和真菌数量显著低于不加菜粕病土(对照),分别降低了20%和68%;而细菌和放线菌数量显著高于对照,分别增加了40%和49%;7 d后生物熏蒸处理和对照土壤中疫霉数量逐渐增加,说明生物熏蒸的最佳时间为7 d。为了增强生物熏蒸的防病效果,通过平板试验筛选了1株既可以拮抗辣椒疫霉又可以抵抗由菜粕降解释放的挥发性杀生气体的铜绿假单胞菌,然后将菜粕与铜绿假单胞菌菌株同时施入土壤中进行7 d的生物熏蒸盆栽试验。发现与生物熏蒸处理相比,生物熏蒸结合铜绿假单胞菌处理的土壤中假单胞菌数量显著增加了401%,疫霉菌的数量显著降低了72%,辣椒疫病的发病率降低了8%。表明生物熏蒸结合施用拮抗菌是一种环保的防控辣椒疫病方法。

To find effective ways to prevent phytophthora blight of pepper caused by Phytophthora capsici, the change of soil microbial population during the process of biofumigation was firstly studied. Biofumigation significantly reduced the population of soil P. capsici and fungi by 20% and 68% respectively, and increased the population of soil bacteria and actinobacteria by 40% and 49% respectively after 7 d. The population of P. capsici in biofumigation treatment gradually increased after the 7th day, indicating that the optimal duration for biofumigation is 7 d. An antag- onistic Pseudomonas aeruginosa was screened by dish culture, which was not only resistant to volatile and toxic gas from rapeseed meal but also antagonistic to P. capsici. The rapeseed meal and P. aeruginosa strains were applied to soil simultaneously for biofumigation for 7 d. Compared with sole biofumigation treatment, the integration of biofumigation with P. aeruginosa strain significantly increased the population of Pseudomonas by 401% and decreased the population of P. capsici by 72% in soil, which contributed to decreasing disease incidence of phytophthora blight of pepper by 8%. Combining biofumigation with antago- nistic microorganism is environmental-friendly to control phytophthora blight of pepper.