蜡质芽孢杆菌R_2防治水稻纹枯病研究

BIOLOGICAL CONTROL OF RICE SHEATH BLIGHT BY BACILLUS CEREUS R_2

选用我们从稻株上分离筛选的能促进水稻生长发育的蜡质芽孢杆菌(Bacillus cereus)R_2号菌株,分别在室内和田间测定其对稻纹枯病菌(Rhizoctonia solani AG—1)的拮抗性和防病效果。在PDBA平板上,R_2对病菌菌丝生长的抑菌带可达10.9mm宽。在WA平板上可抑制病菌菌核萌发,R_2菌量为4×10~6、2×10~7、2×10~9cfu/ml时,病菌菌核萌发菌丝指数分别较对照降低28.2%、39.7%、56.4%。用菌量为2×10~9cfu/ml的R_2菌液处理人工接种病菌的离体稻叶,对纹枯病病斑扩展的控制效果为55.5%,随R_2菌量降低,其控制效果相应递减。用菌量为4×10~7cfu/ml的R_2菌液喷施田间人工接种病菌的稻株,对纹枯病的防效可达43.8%。

The evaluation of antagonistic effect of Bacillus cereus R_2 on Rhizocioniasolani AG-1 has been made in our laboratory and in the field R_2 was isolatedfrom rice plants and demonstrated to have the ability of promoting growthand increasing Yield of rice.R_2 intensely inhibits growth of mycelia of thepathogen on PDBA with an inhibitory zone of 10.9mm in width;it also suppresses germination of the sclerotia.A 43.8% relative control efficiencywas obtained when 4X10^7 cfu/ml R_2suspension was sprayed on plants previously inoculated with mycelia blocks of the pathogen,in comparision with theRhizoctonia-inoculated but R_2 unsprayed check.