察尔汗盐湖嗜盐菌CEH-ST79对马铃薯干腐病的抑制活性及鉴定

Inhibitory activity against potato dry rot and identification of halophilic bacteria CEH-ST79 isolated from Qrhan Salt Lake

为了进一步明确察尔汗盐湖嗜盐菌CEH-ST79对马铃薯干腐病的生防效果,以3株马铃薯干腐病病原菌为指示菌,分别采用平板对峙培养法、牛津杯法和马铃薯活体实验测定嗜盐菌菌株CEH-ST79、发酵液及其提取物对马铃薯干腐病的体外及活体抑制活性。结果表明:菌株CEH-ST79对3株马铃薯干腐病病原菌具有强抑制活性,抑菌带宽为0. 19～0. 33 cm;其发酵液提取物具有较强抑制活性,抑菌带宽为0. 41～0. 70 cm;菌株CEH-ST79发酵液对病原真菌65B-2-6的抑制活性最高,抑制率为73. 83%;菌株CEH-ST79发酵液的乙酸乙酯提取物对病原真菌65B-2-6的抑制活性最高,抑制率为81. 04%。通过形态学、生理生化特征及分子生物学鉴定,确定菌株CEH-ST79为简单芽孢杆菌Bacillus simplex。本研究表明菌株CEH-ST79是一株对马铃薯干腐病具有强抑制活性的嗜盐菌,可进一步将其开发为生防杀菌剂。

In order to clarify the biological effect of strain CEH-ST79isolated from Qrhan Salt Lake on Potato Dry Rot,using three pathogenic fungi of potato dry rot as the indicator fungi,the inhibitory activities of strain CEH-ST79,its fermentation and extract from its fermentation were determined by dual-culture,oxford cup methods and potato trail in vivo.The results showed that strain CEH-ST79had strong inhibitory activity against three pathogenic fungi of potato dry rot,with inhibition zones0.19~0.33cm;the extracts from fermentation of strain CEH-ST79had stronger inhibitory effect,with inhibition zone0.41?0.70cm;the fermentation of strain CEH-ST79had the highest inhibitory activity against pathogenic fungus65B-2-6,with inhibition rate73.83%;the ethyl ace-tate extracts from fermentation of strain CEH-ST79had the highest inhibitory activity against patho-genic fungus65B-2-6,with inhibition rate81.04%.Based on morphological,physiological and biochemical characteristics and molecular identifications,strain CEH-ST79was identified as Bacil-lus simplex.In conclusion,strain CEH-ST79was a halophilic bacterium with strong inhibitory ac-tivity against potato dry rot,which could be developed as biological antibactericide in the future.