梨轮纹病拮抗细菌的筛选与评价

Screening and evaluation of antagonistic bacteria against Botryosphaeria berengeriana f. sp. piricola

采集南京、连云港、高邮3地梨园病叶、病果、健叶、健果、病枝、健枝和土壤样本90份,分离纯化后得到871个细菌分离物,对其进行梨轮纹病菌菌丝生长的皿内抑制试验,共获得21株拮抗能力较强的细菌,其中拮抗性能最好的细菌sf 628抑菌圈直径达45 mm,抑制率达59.21%。梨果接种试验结果表明,21株拮抗能力较强的细菌中有5株拮抗细菌对梨轮纹病菌引起的病斑扩展抑制率大于50%,其中菌株sf 628抑制率达60.61%。进一步的理化特性和分子鉴定结果表明,菌株sf 628为枯草芽孢杆菌枯草亚种。

Biological control on plant diseases could reduce the residue of chemical pesticides and protect natural ecological environment. Pear ring rot is one of common diseases in pear production. The aim of this study was to screen and evaluate the antagonistic bacteria against Botryosphaeria berengeriana f. sp. piricola, which caused pear ring rot. 871 strains were isolated and purified from the diseased leaves,the diseased pomes,the healthy leaves,the healthy pomes, the diseased tress,the healthy tress and the soil from the orchards in Nanjing, Lianyungang and Gaoyou, Jiangsu Province. Antagonistic examination against B. berengeriana f. sp. piricola revealed that 21 strains of all tested strains showed strong and steady antagonism. Strain sf 628 of 21 strains could inhibit the mycelia growth of B. berengeriana f. sp. piricola effectively with 45 mm inhibition zone and the inhibition rate 59.21%. The inoculating experiments on pear pomes showed that five strains of 21 tested strains could inhibit effectively necrosis spread of B. berengeriana f. sp. piricola with the inhibition rate more than 50%, and the inhibition rate of strain sf 628 reached 60.61%. The physicochemical property and molecular （16S rDNA ）identification experiments indicated the strain sf 628 was Bacillus subtilis subsp, subtilis.