噬菌体鸡尾酒联合生物有机肥防控番茄青枯病的效果研究

Biocontrol of phage cocktail combined with bio-organic fertilizer on tomato bacterial wilt

摘要:

[背景] 前期研究表明，可专性侵染青枯菌的噬菌体鸡尾酒（组合）可有效减少番茄青枯病的发生。生物有机肥虽然可降低青枯病发病率，但受田间环境影响，防控效果常不稳定。[目的] 为了提高生物有机肥的防控效果，靶向抑制番茄青枯病，探究噬菌体鸡尾酒联合含有解淀粉芽孢杆菌的生物有机肥防控番茄青枯病的田间效果，以及该防控方法对番茄根际细菌群落结构的影响。[方法] 将经解淀粉芽孢杆菌T-5二次发酵获得的生物有机肥（Bio-organic fertilizer，BOF）在春季作为基肥施入番茄大棚，开花期在番茄根部浇灌噬菌体鸡尾酒悬液，统计青枯病的发生情况和番茄根际青枯菌的数量，根据高通量测序结果分析番茄根际细菌群落的结构变化。[结果] 与常规施肥相比，生物有机肥配合噬菌体鸡尾酒（BOF+P）可显著降低番茄青枯病的发病率，显著改变根际细菌群落的β多样性，提高拟杆菌门（Bacteroidetes）的相对丰度，并降低芽单胞菌门（Gemmatimonadetes）的相对丰度。[结论] 噬菌体鸡尾酒可显著提升生物有机肥防控番茄青枯病的效果，具有良好的应用潜力。

关键词:噬菌体鸡尾酒;生物有机肥;土传青枯病;生物防控

Abstract:

[Background] Previous studies have shown that phage cocktails (multi phage combinations) specifically infecting Ralstonia solanacearum significantly reduce bacterial wilt occurrence. Though bio-organic fertilizer (BOF) can suppress disease incidence of bacterial wilt, its inhibitive effects are not stable due to complex environment in the fields. [Objective] In order to improve biocontrol efficiency of BOF and targeted suppress bacterial wilt, we explored the effect of phage cocktail combined with bio-organic fertilizer fermented by Bacillus amyloliquefaciens on the biocontrol of tomato bacterial wilt. Meanwhile, impacts of this method on the population of R. solanacearum and the bacterial community in the rhizosphere was also investigated. [Methods] BOF obtained by the secondary fermentation of B. amyloliquefaciens T-5 was applied as a base fertilizer in spring in the greenhouse. Phage cocktail which contained four lytic phages of R. soalanacearum were soil-drenched during the flowering period of tomato. The incidences of bacterial wilt and the abundance of R. solanacearum in tomato rhizosphere were measured. Changes of bacterial communities were analyzed via high-throughput sequencing. [Results] Compared with conventional fertilization, the combination of bio-organic fertilizer and phage cocktail (BOF+P) significantly reduce diseased the incidence of tomato bacterial wilt. Beta-diversity was significantly changed after treated with BOF+P, among which relative abundance of Bacteroidetes increased but Gemmatimonadetes reduced. [Conclusion] Phage cocktail combined can improve bio-control efficiency of BOF significantly, which indicates an application potential.

Key words:phage cocktail;bio-organic fertilizer;soil borne bacterial wilt;biocontrol