拮抗细菌菌株B5423和Pf7-14对稻瘟病的防效及其在稻株上的种群动态

首先测定了离体条件下6个拮抗细菌菌株对水稻稻瘟病菌、纹枯病菌、恶苗病菌和白叶枯病菌的抑制作用。然后,在温室条件下测定了上述6个菌株对水稻稻瘟病的防治效果,并以菌株B5423和Pf7-14为代表,测定了这两个菌株在稻株上的种群动态。结果表明,上述6个菌株对水稻主要病原菌有着不同程度的抑制作用;菌株B5423对水稻稻瘟病的防效最好,施用后7d、14d的防效分别为56.23%和49.25%,显著地高于其他5个菌株;在相同的浓度下,Pf7-14(对抗生素萘啶酮酸具有天然的抗性)在稻株上的定殖能力比B5423-R(B5423的利福平抗性的突变体)强。

Control Effects of Antagonistic Bacteria Strains B5423 and Pf7-14 on Rice Blast and Their Population Dynamics on Rice Plants

In the paper the authors first measured the inhibitory effects of 6 antagonistic bacteria strains (5 Bacillus spp, and 1 Pseudomonas sp.) on Magnaporthe grisea, Rhizoctonia solani, Fusarium moniliforme, and Xanthomonas oryzae pv. oryzae in vitro, then conducted the experiments in controlling rice blast by the above 6 strains and monitoring the population dynamics of Bacillus subtilis B5423-R, the marking strain of B5423 (the mutant of Rifampicin-resistance), and Pseudomonas fluorescens Pf7-14 on rice plants under greenhouse conditions. The results showed that the above 6 bacteria strains inhibited rice pathogens to a different degrees, of 6 strains, B5423 was the best, its control effect on rice blast on the seventh and fourteenth day after spraying was 56.23% and 49.25% respectively, significantly higher than that of any other strains; and the colonization ability of strain Pf7-14 is stronger than that of B5423 at the same introduced concentration.