拮抗细菌菌株Bacillus spp.间的相互作用及其对水稻纹枯病的抑制

Interaction among antagonistic Bacillus spp. strains and their suppression against rice sheath blight

测定了6个Bacillus spp.和1个Pseudomonas sp.P-13(G-对照菌株)在PPM培养基上的相互作用。在总共42个组合中,有27个组合是可亲和性的。在以B5423为单剂之一的5个组合中,亲和性的组合有4个。在温室条件下通过分批播种,在水稻分蘖盛期喷以B5423-R(B5423的标记菌株,是利福平抗性的突变体)为单剂之一的4个亲和性组合的菌悬浮液,以检测该组合中B5423-R在水稻茎基部的种群数量。结果发现,与单剂B5423-R相比,在应用1～7天内,组合B5423-R+B45中,B5423-R的群体数量显著性降低;组合B5423-R+B95、B5423-R+B77中,B5423-R的群体数量与单剂无显著差异;组合B5423-R+B4313中,B5423-R的群体数量在应用1～4天内与单剂无显著性差异,但在应用第7天显著地高于单剂。离体叶片纹枯病病斑面积的抑制试验表明,与各自的单剂相比,组合B95+B5423及B95+B77显著地抑制了纹枯病病斑面积;而组合B45+B80、B45+B5423和B45+B95纹枯病病斑面积显著地高于各自的单剂;其余10个组合与各自的单剂无显著差异。

: Six Bacillus spp. (B. subtilis B5423, B. subtilis B77, B. cereus B45, B. Cereus B95, B. Cereus B80, and B. Cereus B4313) strains and one Pseudomonas sp. P-13 (check strain) strain were measured in terms of their in vitro inhibition against each other on PPM plates. Of 42 combinations, 27 are compatible and 15 are incompatible combinations. Of 5 combinations containing B5423, four are compatible and one is an incompatible combination. The population dynamics of B5423-R (B5423-R, a rifampicin-resistant mutant, is the marking strain of B5423) on rice stems used in the four compatible combinations were monitored by spraying the suspension of the different combinations. In two trials, it was found that population size of B5423-R on rice stems used in combination with B45 was significantly lower than that of individual B5423-R within 7 days after their application. Those in the combinations B5423-R + B95 and B5423-R + B77 are not significantly different from individual B5423-R within 7 days after their application. On the other hand, the population size of B5423-R in the combination B5423-R + B4313 is not significandy different from individual B5423-R population within 4 days after their application, but are significandy higher at 7 days after their application. Combinations B95 + B5423 and B95 + B77 significandy suppressed the lesion area of sheath blight of rice in detached leaves, while combinations B45 + B80, B45 + B5423 and B45 + B95 significandy increased the lesion area. The other 10 combinations are not significandy different from dieir respective single agents.