一株抗真菌内生多粘芽孢杆菌的分离鉴定及对水稻恶苗病菌的抑制作用

Identification of an Endophytic Paenibacillus polymyxa Strain Producing Antifungal Protein and the Inhibition to Fusarium moniliforme causing Rice Bakanae Disease

目的:从番茄叶片中筛选具广谱抑真菌活性的拮抗内生细菌,研究其对水稻恶苗病菌的抑制作用。方法:采用对峙培养法筛选拮抗内生细菌,根据菌株形态、生理生化特性结合16S rRNA基因序列分析鉴定菌株;采用硫酸铵沉淀法提取抗菌粗蛋白,研究其对水稻恶苗病菌菌丝生长和孢子萌发的影响。结果:从番茄叶片中筛选到一株抗真菌内生多粘芽孢杆菌(Paenibacilluspolymyxa)SD-6,该菌株具有广谱抑菌活性,对供试的13种植物病原真菌均具较强的抑制作用;该菌株产生的抗菌粗蛋白能够显著抑制水稻恶苗病菌菌丝生长和孢子萌发,并能导致萌发孢子畸形和破裂。结论:从番茄叶片中分离到一株能产生抗真菌蛋白并具有广谱高效抑真菌作用的内生多粘芽孢杆菌,该菌株及其抗菌蛋白具有防治水稻恶苗病的潜力。

An antagonistic endophytic bacterium,designated as strain SD-6,was isolated from healthy tomato leaves using dual culture method.Based on phenotypical and biochemical properties as well as its 16S rRNA gene sequence,the bacterium was identified as Paenibacillus polymyxa.In vitro antifungal spectrum assay vindicate that it was active against a broad range of phytopathogens and inhibited the growth of thirteen fungal pathogens.In order to further evaluate the biocontrol potential against rice bakanae disease caused by Fusarium moniliforme,crude protein was extracted from fermentation broth using ammonium sulphate precipitation.The crude protein inhibited the mycelial growth and spore germenation of F.moniliforme,and caused distortion,tumescence of a portion of the germinated spores.This is the first report about isolating an antagonistic endophytic P.polymyxa from tomato leaves,which produced antifungal protein and possessed the inhibitory activity against a wide range of fungal pathogens.The protective properties of selected P.polymyxa strain make it as potential tool to reduce deleterious impact of fungal diseases.The strain SD-6 and associated proteins are potentially useful in controlling rice bakanae disease.