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为了寻求新的生物防治菌种资源,以醋糟基质为试验材料,采用稀释涂布平板法从醋糟中分离出对立枯丝核菌具有明显抑制作用的拮抗菌,采用平板对峙法研究其对病原菌的广谱抑制效果,将菌体特征与16SrDNA序列分析及生理生化指标相结合,对拮抗菌进行初步鉴定,确定其分类地位,采用温室盆栽试验对分离的拮抗菌进行抗病促生效果初探。结果表明:从醋糟中分离到了1株对立枯丝核菌具有明显拮抗作用的菌株CZ,且菌株CZ具有广谱的抑菌效果,对西瓜枯萎病、香瓜枯萎病、黄瓜枯萎病、水稻恶苗病、小麦赤霉病、苹果炭疽病原菌都具有较强的拮抗作用。根据菌体特征、16SrDNA序列分析及生理生化指标的结果,初步鉴定该菌为死谷芽孢杆(Bacillus vallismortis CZ)。温室盆栽试验表明菌株CZ对由立枯丝核菌引起的黄瓜立枯病具有显著的抑制效果,与对照组相比,接种菌株CZ后,黄瓜小苗的病情指数降低了18.3%。由此可见,菌株Bacillus vallismortis CZ具有开发成生防试剂的潜力。
In order to seek new biological control germplasm resources, vinegar-based substrate was used as test material, and the antagonistic bacterium that had obvious inhibitory activity against Rhizoctonia solani was isolated from vinegar grains by dilution coating method. The broad-spectrum inhibitory effect of pathogenic bacteria, bacterial characteristics and 16SrDNA sequence analysis and physiological and biochemical indicators of the combination of preliminary identification of antagonistic bacteria to determine its taxonomic status, the use of greenhouse pot experiments on the antagonistic bacteria to promote disease resistance . The results showed that one strain CZ with obvious antagonism against Rhizoctonia solani isolated from vinegar grains and the strain CZ had broad-spectrum antibacterial activity against watermelon blight, melon wilt, cucumber wilt, Miao disease, wheat scab, Apple anthracnose pathogens have a strong antagonistic effect. According to the characteristics of mycelium, 16S rDNA sequence analysis and physiological and biochemical indicators, it was initially identified as Bacillus vallismortis CZ. Pot experiments in greenhouse showed that strain CZ had a significant inhibitory effect on R. cucumber blight caused by Rhizoctonia solani. Compared with the control, the disease index of cucumber seedlings decreased 18.3% after inoculated with strain CZ. Thus, the strain Bacillus vallismortis CZ has the potential to develop as a biocontrol agent.