荧光93菌体和代谢物对全蚀病菌和小麦生长影响的初步研究

EFFECTS OF PSEUDOMONAS FLUORESCENS D93 STRAIN AND ITS METABOLITES ON GAEUMANNOMYCES GRAMINIS AND GROWTH OF WHEAT

对荧光假单胞菌工程菌剂“荧光93”菌体和代谢物的作用特性进行了比较。结果表明:该菌剂能保护小麦根系免遭全蚀病危害,对植株生长有促进作用。菌体的抑菌能力强于代谢物,浸种处理防效分别为44.8％和27.8％;代谢物具有更强的刺激植株生长作用,在无病条件下,代谢物灌根处理鲜重增加34.5％,菌体处理鲜重增加7.5％。培养基成份对代谢物的作用有一定影响:以马铃薯葡萄糖培养产生的代谢物,抑菌效果好;营养肉汁酵母粉培养产生的代谢物,促生作用好。据此推断,荧光93菌剂代谢产物中含有抑制全蚀病菌和刺激植株生长的物质。

The role of Pseudomonas fluorescens strain D93, a genetically engineered microorganism, was compared with its metabolites. This biocontrol agent protected roots of wheat from attack by the take-all pathogen and stimulated growth of wheat in the greenhouse experiments conducted in Beijing. Seed treatment with the bacteria and the sterile metabolites reduced the disease severity by 4.8% and 27.8%, respectively. Soil treatment with the metabolites and the bacteria increased the fresh top weight of wheat seedlings by 34.5% and 7.5%, respectively. The results indicate that if used at the same concentration, the bacteria are better than the metabolites in disease suppression, while the metabolites are more suitable than the bacteria for plant growth stimulation. The effect of metabolites was influenced by the ingredients of the culture media. The disease-inhabiting ability of the metabolites produced in potato dextrose was greater than that of the metabolites produced in nutrient broth yeast. In contrast, the ability of the former to stimulate wheat growth was weaker than that of the latter. It was concluded that some unknown materials in the metabolites of strain D93 were involved in disease suppression and wheat growth stimulation.