解淀粉芽胞杆菌HR-2的分离鉴定及对水稻稻瘟病菌的拮抗效果

稻瘟病是一种严重威胁全球粮食安全的水稻真菌病害。本研究采用平板对峙法从湖南岳阳地区筛选出1株对水稻稻瘟病菌具有高效拮抗活性的菌株HR-2。通过形态特征验证、16S rRNA、gyrA和tuf基因序列比对分析,鉴定该菌株为解淀粉芽胞杆菌(Bacillus amyloliquefaciens)。抑菌广谱性测定结果表明菌株HR-2对水稻稻瘟病菌、油菜菌核病菌和番茄青枯病菌均有较强的拮抗效果,抑制率分别为82.34%、72.32%和72.64%。盆栽试验结果显示,菌株HR-210倍稀释液和100倍稀释液对水稻稻瘟病的防治效果分别达到63.81%和40.77%,其中HR-210倍稀释液的防效与50 mg/L嘧菌酯的防效相当。试验结果表明解淀粉芽胞杆菌菌株HR-2抑菌谱广,尤其对水稻稻瘟病具有显著的防治效果,可为抗稻瘟病生物防治药剂的开发奠定基础。

Isolation and Identification of Bacillus amyloliquefaciens HR-2 and Biological Control of Rice Blast

Magnaporthe oryzae is a rice fungal disease that seriously threatens global food security.A strain HR-2 with high antagonistic activity against M.oryzae was screened from Yueyang district,Hunan province by plate confrontation method in this study.The strain HR-2 was identified as Bacillus amyloliquefaciens by morphological verification,16S rRNA,gyrA and tuf gene sequence analysis.The results of broadspectrum inhibition showed that the strain HR-2 had a fine inhibitory effect on M.oryzae,Sclerotinia sclerotiorum and Ralstonia solanacearum,and the inhibition rates were 82.34%,72.32%and 72.64%,respectively.The results of pot experiment demonstrated that the control effects of HR-210-times diluted solution and 100-times diluted solution on M.oryzae were 63.81%and 40.77%respectively,among which the control effects of HR-210-times diluted solution were similar to that of 50 mg/L azoxystrobin.The above results indicated that B.amyloliquefaciens HR-2 had a wide antibacterial spectrum and an obvious control effect on M.oryzae.Our research lays a foundation for the development of biological control agent against M.oryzae.