| Bacillus sp.can secret a variety of antibacterial substances,induce fruits resistance and form endospores,which can promot the growth of plant.So,it can be used as the ecofriendly antagonistic preservative ingredients.This research systematically explores the causes of post-harvest loquat decay caused by a variety of spoilage fungi and screens the antagonistic bacteria.Eight kinds of spoilage strains were isolated,purified and identified by ITS DNA test.These testing molds were Fusarium oxysporum,Phoma sp.,Botryosphaeria sp.,Trichoderma atroviride,Colletotrichum acutatum,Penicillium expansum,Penicillium citrinum,and Colletotrichum gloeosporioides.Strain B4 and B6 can inhibit the growth of eight molds in vitro and six kinds of molds in vivo.B4 was Bacillus amyloliquefaciens and B6 was Bacillus subtilis according to 16S rDNA analysis.B4 and B6 were non-toxic and had no effect on feed intake and body weight of mice by acute oral toxicity and 28 d feeding experiments.Natural corruption experiments in 20 d showed that B4 and B6 broth can delay the loquat postharvest disease and the incidence decreased by 37.5%and 12.5%,respectively.Loquat tissue treated with Bacillus B4 was smoother and less susceptible to pathogen infection through scanning elecreon microscopy.The suspension of B4 can significantly inhibit the growth of molds by site occupying,antibiotics secretion and enhancement of protective enzymes'activity.SigM,one of ECF regulators recognized in B6,can regulate the production of the fungistatic agent.B6 supernatant also improved the acitivity of CHI,PPO and decreased the activity of POD. |
PDF Full Text Request