盐碱土锈腐病拮抗菌的筛选和鉴定

Screening and Identification of Antagonistic Bacteria for Rust Rot from Saline-alkali Soil

[目的]对黑龙江省大庆地区盐碱土壤进行嗜(耐)盐碱菌的筛选。[方法]采用不同Na Cl浓度梯度的Sehgal-Gibbons平板筛选,利用琼脂块法获得对人参锈腐病病原菌有拮抗作用的嗜(耐)盐碱菌株,并将传统的形态学观察与现代分子生物学技术相结合对其进行鉴定。[结果]从大庆地区盐碱土壤中共分离出48株细菌,其中60.4%的菌株为耐盐菌,其余为中度嗜盐菌。所有菌株的耐碱能力在pH 8.0~11.0,其中64.6%的菌株耐碱能力高达pH 11.0,除2株为嗜碱菌,其余均为耐碱菌。人参锈腐病毁灭柱孢菌R2拮抗性筛选获得3株菌,经形态学、生理生化特征及16SrRNA基因序列的系统发育分析,确定3株菌分别为Halomonas elongata、Halomonas xianhensis和Oceanobacillus iheyensis。[结论]从盐碱土中获得3株对人参锈腐病有拮抗作用的嗜(耐)盐碱菌,并进行了鉴定。

[Objective] Haloalkaliphilic bacterial strains were screened from saline-alkali soil in Daqing City, Heilongjiang Province.[ Meth-od] Strains were screened with plate dilution method on different NaCl concentration gradient Sehgal-Gibbons medium.The haloalkaliphilic bacteria with antagonistic activity against rust rot was obtained by plate confrontation method and identified based on morphological observation and modern molecular biology techniques.[Result] 48 strains of bacteria were isolated from saline-alkali soil in Daqing City, 60.4% of the strains were grouped into the halotolerant bacteria, and the rest into the moderate halophiles.Alkaline resistance of the strains was between pH 8.0 and 11.0, 64.6% of which pH tolerance reached to pH 11.0.The rest was alkali-resistant bacteria except two basophilic bacteria.3 strains were obtained by screening antagonistic activity of rust rot C.destructans R2.Morphology,physiological and biochemical characters and phylogeny of 16SrRan gene sequence were analyzed.3 strains were identified as Halomonas elongate,Halomonas xianhensis and Oceanobacillus iheyensis.[Conclusion] 3 haloalkaliphilic bacterial with antagonistic activity against rust rot were screened and identified from saline-alkali soil.