柑桔溃疡病拮抗芽孢菌株的筛选及其控病作用

从贛州脐橙园脐橙根际土壤中获得192个细菌分离物,通过平板拮抗测试,筛选出对柑桔溃疡病菌Xanthomonas axonopodis pv.citri有较强拮抗作用的6个芽孢菌株,抑菌圈直径达12.0～25.0mm,其中菌株G32对柑桔溃疡病菌抑制效果最好,稳定性高;温室控病试验表明,菌株G32的控病效果最佳,接种溃疡病菌前喷施拮抗菌G32的预防效果达60.7%,接种溃疡病菌后喷施拮抗菌G32的治疗效果为53.2%;根据其形态特征、培养性状、生理生化特性及16SrDNA序列比对分析,将G32鉴定为枯草芽孢杆菌Bacillus subtilis。 192 isolates were obtained from rhizosphere soil of citrus orchards in Ganzhou, Jiangxi province. It was found that 6 potential biocontrol spore bacteria showed good antagonistic effect on Xanthomonas axonopodis pv. citri, the pathogen of citrus bacterial canker, for showing inhibition zones of 12. 0 mm to 25.0 mm in diameter by pairing culture on NA plate. The bacterial strain G32 had the best inhibitory effect on the pathogen and the highest stability. The control rate of strain G32 reached 60. 7% and 53.2% respectively when sprayed prior to and after the inoculation of citrus canker bacteria under greenhouse conditions. Based on morphological, cultural, physiological and bio- chemical characteristics, as well as its 16S rDNA sequence, G32 was identified as Bacillus subtilis.