两株生防荧光假单胞杆菌的室内筛选试验

Experiments on the Screening of Two Antagonistic Strains of Pseudomonas fluorescent in the Laboratory

从番茄根际土壤中筛选出11株对水稻稻瘟病菌具拮抗活性的细菌原始菌株,其发酵滤液对稻瘟菌菌丝生长抑制率达50％以上的菌株有8个。依据拮抗活性测定结果,确定AbⅢ745和AbⅢ763的单胞分离后代AbⅢ745-6和AbⅢ763-1为最优菌株,其对稻瘟病菌的抑制率分别达96.88％和78.57％,对小麦全蚀病菌、小麦根腐病菌及番茄早疫病菌也有一定的抑制作用。经初步鉴定,AhⅢ745-6和AbⅢ763-1属于假单胞菌科荧光假单胞杆菌。

Eleven antagonistic bacterial strains which inhibit Pyricularia oryzae were screened out from rhizosphere soil. A result of over 50% suppression of the indicator pathogen was obtained among eight of those effective original strains, with the treatment of their fermentation filtrate. According to the result of the determination of antagonistic activities, Ab Ⅲ 745-6 and AbⅢ763-1,the single-cell isolated offsprings of AbⅢ745 and AbⅢ 763,were regarded as the idealest ones. They could inhibit the growth of mycelia of Pyricularia. oryzae with effect of 96. 88% and 78. 57% respectively. Also, antagonistic activities a-gainst Gaeumannomyces graminis var. trici, Drechslera sorokiniana, Alternaria solani were showed in the in vitro tests. The strongest antagonistic strains,namely AbⅢ745-6 and AbⅢ763-1 ,were identified as Pseudomonas fluorescent.