植物真菌病害是影响农业生产的主要因素之一,连作栽培导致病害逐年加重,为获得能够抑制病原真菌的生防菌以解决真菌病害防治难题,通过平板对峙实验及分子鉴定、抑菌活性物质分析、葡聚糖酶基因克隆及分析,获得一株对多种植物病原真菌具有显著抑制作用的芽孢杆菌,菌株编号为L103。16S rDNA及看家基因序列分析表明,该菌株为巨大芽孢杆菌,羧甲基纤维素钠平板筛选及刚果红染色实验发现该菌具有很强的产纤维素酶(CMC酶)的能力,根据GenBank中巨大芽孢杆菌内切葡聚糖酶基因(HM130670.1)序列设计引物,将扩增得到的1482bp大小的片段克隆到载体pMD18-T上,测序并通过GenBank数据库BLAST分析显示该序列与一株Bacillus sp. HB102的内切β-1,4-葡聚糖酶基因序列一致性达到95%,而与Bacillus subtilis的β-1,4-内切葡聚糖酶基因一致性为85%,进一步分析该菌株产生的抗病活性物质并对其进行改良将为该菌在今后的真菌病害防治应用中提供理论基础。

Plant fungal diseases are the main factor that affects agricultural production. In order to inhibit fungus diseases, the flat confrontation experiment and the molecular detection were employed for the isolation of biocontrol bacteria. Bacillus L103 was isolated from a vegetable field in suburb of Beijing. The antimicrobial spectrum suggests that this strain shows a high level of inhibitory activity against the tested plant pathogenic fungi. The analysis of 16S rDNA and housekeeping gene sequence shows that it is a kind of Bacillus megaterium. It could produce β-1,4-glucanase, that was detected on CMC-Na plates and congo red staining. We amplified the endo-β-1,4-glucanase gene and sequenced it according to GenBank No.HM130670.1. Its full length was found to be 1482bp and its amino acid number is about 494. Its endo-β-1,4-glucanase gene sequence has 92％ homology with that of the endo-β-1,4-glucanase gene of Bacillus sp. HB102, and 85% homology with that of Bacillus subtilis.