水稻纹枯病拮抗细菌的筛选与利用

稻种是生防菌的主要来源之一,为在浙江稻区获得对水稻纹枯病具良好防治效果的生防菌,有必要明确该稻区不同栽培方式下稻种拮抗菌的分布及其特性.从3种不同栽培方式的稻种上分离并测定水稻纹枯病拮抗细菌,发现撒播稻稻种上拮抗菌比率显著高于条播和移栽稻.从1000个细菌分离物中筛选出13个拮抗能力强的菌株,经致病性测定发现S270262在水稻植株上产生病斑;对12个非致病拮抗菌进行稻种细菌化、盆栽测定和田间小区试验及Biolog鉴定,结果表明10个拮抗菌对稻苗具促生作用,2个有抑生作用;盆栽和田间防治效果好的菌株为T300363、S300265和S90132,它们分别被鉴定为Salmonella subsp.1 G、Pseudomonas aeruginosa和Pseudomonas spp..

Screening and utilization of antagonistic bacteriae against rice sheath blight

Rice seed is one of the most important resources of biocontrol agents.It's necessary for us to understand distribution of the antagonistic bacteria against sheath blight of rice under different culture pat- terns and their characteristics in order to gain satisfied biocontrol agents in Zhejiang Province.A field survey and isolation of the antagonistic bacteria was conducted.It was showed that the isolation frequency of the antagonistic bacteria from rice seeds of direct broadcast-seeding was significantly higher than those from direct row-seeding and transplanting.Thirteen strong antagonistic bacteriae against Rhizoctonia sola- ni were screened in vitro from 1000 bacterial isolates obtained from 3 different culture patterns of rice. Pathogenicity test showed that isolate S270262 produced lesions on rice plant and other 12 strains were non-pathogenicity,which were used for rice seed bacterization against R.solantiv in the screening-house and greenhouse and spraying in paddy field and identified by Biolog.The results showed the 10 strains had growth promoting effect on rice plant and 2 inhibiting the growth.Strain T300363,S300265 and S90132 had better performance in pot and field plot experiments.They were identified by Biolog as Sal- monella subsp.1 G,Pseudomonas aeruginosa and Pseudomonas spp.