巨大芽孢杆菌对商洛烤烟生长及土壤微生物的影响

以''云烟99''为试验材料，应用高通量测序技术，主要研究巨大芽孢杆菌及不同施用量对商洛烟田土壤微生物群落特征、烤烟生长及产质量的影响。结果表明，施用巨大芽孢杆菌可有效促进烤烟生长，提高烤烟产量、产值、均价及上等中等烟比例，显著增加烤烟经济效益，其中6 kg/667m处理效果最佳。土壤微生物测序结果表明，该区域土壤微生物主要优势菌群为变形菌门和放线菌门，该优势贯穿烤烟整个生育期，另有酸杆菌门、芽单胞菌门、绿弯菌门、厚壁菌门、拟杆菌门等在特定时期表现出一定的优势，本试验所用的巨大芽孢杆菌属于厚壁菌门，该菌在施用后30 d表现为优势菌群，随着生育期的推进优势逐渐减弱。此外，各菌剂处理微生物多样性指数均显著高于对照，且各处理间微生物群落结构差异显著（P<0.05）。综上所述，巨大芽孢杆菌的应用有效地促进烟草生长，提高了烟草品质，并对土壤微生物群落结构产生显著的影响，研究结果可为该地区微生物菌剂的应用与研究提供理论基础。

Effects of Bacillus megaterium on Growth of Flue-cured Tobacco and Soil Microorganisms in Shangluo

Taking ''YN99'' as the test material, the effects of Bacillus megaterium and its different application rates on soil microbial community characteristics, growth and quality of flue-cured tobacco in tobacco field of Shangluo were explored . The high-throughput sequencing method was used to study soil microbial community characteristics. The results showed that the application of Bacillus megaterium could effectively promote the growth of flue-cured tobacco and increase the yield, output value, average price and the proportion of prime and medium tobacco. In addition, the economic benefit of flue-cured tobacco was significantly increased. The treatment with 6 kg/667m Bacillus megaterium performed the best. The sequencing results showed that the dominant bacteria phyla were Proteobacteria and Actinobacteria, its advantages lasted for the whole growth period of tobacco. Besides, the Acidobacteria, Bacillus, Chloroflexi, Firmicutes and Bacteroidetes etc. showed some advantages in certain growth period of tabacco.Bacillus megaterium used in this research belonged to Firmicutes, which was a dominant phylum at 30 days after application. However, the advantage gradually weakened with the advance of the growth period. In addition, the microbial diversity index of each treatment was significantly higher than that of the control treatment. The microbial community structure of each treatment was significantly different each other(P<0.05). In conclusion, the application of Bacillus megaterium can effectively promote the growth of tobacco, improve the quality of tobacco, and has a significant impact on the soil microbial community structure. The results can provide a theoretical basis for the application and research of microbial agents in this area.