【摘要】 土壤中存在大量有益的拮抗细菌。将纹枯菌菌核埋入稻田中可富集拮抗菌,经分离、筛选和测定,并通过拮抗细菌悬浮液抑制纹枯菌菌核萌发、种子细菌化处理等试验,获得了91、31-2、23和204等4个较好的拮抗细菌菌株。对纹枯病菌的拮抗带分别为10.0、12.7、6.7和11.0毫米;萌发率分别为22.9％、42.9％、28.6％和60.0％。应用后,水稻植株上的纹枯病的病斑高度,比对照分别低14.0％、22.4％、11.8％和16.4％;恶苗病徒长苗数比对照分别减少55.7％、49.2％、32.8％和50.8％。更多还原

【Abstract】 Great amount of antagonistic bacteria exist in the soils of paddy fields. Sclerotia of Rhizoctonia solani were buried in the paddy soil in Jiangsu Province and four promising bacterial isolates were obtained, viz. 91, 31-2, 23 and 204. The diameters of their inhibition zones against R. solani were 10.0 2.7, 6.7 and 11.0 mm, respectively. Submerging the sclerotia of R. solani in suspensions of the bacterial isolates (at 1×1011 cfu/ml) at 25°C for 24 hr. resulted in 22.9%, 42.9%, 28.6% and 60.0% germination rate of the pathogen for the four isolates, respectively. In the potted experiments of treating rice seeds with the four isolates, the sheath blight infection incidence on the seedlings was reduced for 14.0%, 22.4%, 11.8% and 50.8%, respectively, and that of bakanae was reduced for 55.7%, 49.2%, 32.8% and 50.8%, respectively.更多还原