几丁质诱导汉逊德巴利酵母拮抗活性的研究

Antagonistic Activity of Debaryomyceshansenii Induced by Chitin

摘要:

为了提高拮抗酵母Debaryomyceshansenii的生物防治能力，通过体外(in vitro)和体内(in vivo)试验，用不同浓度的几丁质跟酵母混合，研究对采后柑橘青霉病(Penicilliumdititatum)的生防效果，以及几丁质对酵母生长繁殖的影响和对几丁质酶的诱导情况。试验结果表明，酵母与几丁质混合后，对柑橘青霉病的防治有显著提高，其中，酵母(107 CFU/mL)与1.2%几丁质混合使用对柑橘青霉病的效果最佳，6 d后刺伤试验的发病率和浸泡试验的腐烂指数分别为15.51%和14.62%，比单独使用酵母(107 CFU/mL)降低了21.13%和14.76%。在液体培养基中加入几丁质对酵母菌的生长繁殖无显著影响，几丁质对酵母在柑橘伤口的生长繁殖均有一定刺激作用，以1.2%的几丁质刺激作用最强，1.2%和1.4%的几丁质与酵母混合都能诱导几丁质酶活性上升。表明D.hansenii与几丁质与混合后，对柑橘采后青霉病的防治有潜在的应用价值。

Abstract:

To improve the biocontrol efficacy of antagonistic yeast Debaryomyceshansenii (D.hansenii), the combination of the yeast with different concentrations of chitin against postharvest diseases caused by Penicilliumdititatum(P.dititatumthan) in orange fruits were investigated in vitro and in vivo. Meanwhile, the population dynamics of D.hansenii and the activity changes of chitinas were tested. The results showed that combining D.hansenii with chitin provided more effective control on P.dititatumthan than that only using the antagonistic yeast, and D.hansenii combined with 1.2% chitin showed the best effect. The disease incidence rate and decay index were 15.51% and 14.62%, respectively after 6 days. Chitin at different concentrations had less inhibit effects on the growth and proliferation of D.hansenii in NYDB medium. The chitin (1.2%) in wounded oranges showed the strongest stimulus for the growth of D.hansenii. And D.hansenii with 1.2% or 1.4% chitin had a positive effect on inducing the increasing activity of chitinas in orange fruits. Therefore, the combination of D.hansenii with chitin may have great potential value against green mold of orange fruits.