水稻纹枯病生防菌的筛选与鉴定

Screening and Identification of Microbes Antagonistic to Rice Sheath Blight Fungus Rhizoctonia solani

从辽宁省、吉林省和黑龙江省多个地区采集水稻田土样。采用3点平板对峙培养法、菌丝生长速率法和菌核萌发抑制法,综合筛选对水稻纹枯病菌有生防作用的生防菌。结果表明:从土壤中分离获得的211株生防菌中筛选出抑菌活性较高的1株真菌JLF6-2和3株细菌JLN3-2、SYN6-3及JLN3-8。4株生防菌株抑菌圈分别为38.30mm、18.30mm、33.30mm和22.50mm;菌丝生长抑制率分别为77.30%、63.29%、80.35%和100%;菌核萌发抑制率分别为86.67%、83.33%、80.00%和61.35%。经离体试验于接种水稻纹枯病菌前后不同时间喷施供试生防菌发酵滤液,结果对水稻纹枯病均有较高的防治效果。在保护处理中,生防菌株的防效为59.65%~94.92%,其中JLN3-2在24h的防效为94.92%;在治疗处理中,生防菌株的防效为59.32%~74.58%,其中JLN3-2在8h的防效为74.58%。经形态特征、生理生化特性和分子生物学鉴定结果表明:菌株JLF6-2为比莱青霉(Penicillium bilaiae);JLN3-2为纺锤形赖氨酸芽孢杆菌(Lysinibacillus fusiformis);SYN6-3为解淀粉芽孢杆菌(Bacillus amyloliquefaciens);JLN3-8为侧孢短芽孢杆菌(Brevibacillus laterosporus)。

The soil samples from several regions of paddy field were collected from Liaoning, Jilin and Heilongjiang provinces.Three methods of flat growth restraint, mycelial growth and spore germination were used to screen biological control agents to Rhizoctonia solani. Three effective biological control potential isolates including one high antibacterial activity fungus（JLF6-2）and three bacteria（LN3-2, SYN6-3 and JLN3-8） were screened from 211 isolates which were separated and purified from the soil sample. Separately, the inhibitory bacteriostatic ring were 38.30 mm, 18.30 mm, 33.30 mm and 22.50 mm. The growth inhibition rates of mycelial were 77.30%, 63.29%, 80.35% and 100%, respectively. The germination inhibition rates of sclerotium were 86.67%, 83.33%, 80.00% and 61.35%, individually. The vitro experiment results showed that it had significant difference before and after inoculation of Rhizoctonia solani when fermentation filtrate was spraying. In protective treatment, the control efficiency of these biological control isolates could reach from 59.65% to 94.92%, especially the JLN3-2 could even reach94.92% with treatment for 24 h. In therapeutic treatment, the control efficiency of these biological control isolates could reach from 59.32% to 74.58%. Also the JLN3-2 could reach 74.58% with treatment for 8 h. All these four isolates was based on develop character and morphological characteristics, physiological and biochemical test, as well as molecular biology assay. The isolate JLF6-2 was identified as Penicillium bilaiae. Also, JLN3-2 was identified as Lysinibacillus fusiformis, SYN6-3 was identified as Bacillus amyloliquefaciens and JLN3-8 was identified as Brevibacillus laterosporus.