防治稻曲病的生物药剂筛选与评价

Screening and Evaluation of Biological Fungicides Against Rice False Smut

为了筛选出防治稻曲病的高效生物药剂,采用菌丝干重法和孢子萌发法测定了7种生物药剂对稻曲病菌菌丝生长和孢子萌发的抑制率,并进行了测试药剂的田间防治试验。结果表明,7种供试药剂在室内测试试验剂量下对稻曲病病原菌菌丝生长抑制率都达80%以上,其中井冈·蜡芽菌、井冈·枯芽菌、枯草芽孢杆菌对稻曲病病原菌菌丝抑制率都为100%;对稻曲病病原菌孢子萌发抑制率在70%以上的生物药剂有井冈·枯芽菌、蛇床子素、井冈·嘧苷素和井冈·蜡芽菌;田间防治效果较好的药剂是井冈·枯芽菌和蛇床子素,两者防效都在70%以上。研究结果证实在破口期前7 d左右和齐穗期前后施用6%井冈·240亿CFU·g^(-1)枯芽菌可湿性粉剂或1%蛇床子素水乳剂,可提高对稻曲病的综合防治效果。

In order to screen the best biological fungicide against Ustilaginoidea virens,efficacy of seven biofungicides was evaluated by mycelial dry weight method,spore germination method and field trials.Indoor bioassay showed that the inhibition rate of seven biofungicides on the mycelial growth of U.virens reached more than 80% under the laboratory test dose,and the inhibition rate of Jinggang Bacillus cereus,Jinggang Bacillus subtilis and Bacillus subtilis on the mycelial growth was 100%.Spore germination assay showed that Jinggang Bacillus cereus,Osthole,Jinggang Pyrimidine Nucleoside and Jinggang Bacillus subtilis significantly affect the elongation of germ tube and its inhibitory rate were above 70%.Field trials demonstrated that Jinggang Bacillus subtilis and Osthole exhibited high control effect,both of which were as high as 70%and effective against rice false smut.It was proved to be an effective way that 6%Jinggang 24billion CFU·g^(-1)Bacillus subtilis WP or 1% Osthole EW was applied in about 7days before the rupturing stage of rice and full heading stage.