Combination of the biocontrol yeast Cryptococcus laurentii with UV-C treatment for control of postharvest diseases of tomato fruit

Integrated management that combines different methods is being actively pursued in the control of postharvest disease. In this study, the biocontrol yeast Cryptococcus laurentii and ultraviolet-C (UV-C) treatment were evaluated for controlling infection following artificial inoculation with Botrytis cinerea or Alternaria alternata, and natural infection in tomato fruit. Applied separately, C. laurentii and UV-C (4 kJ m(-2)) effectively inhibited decay caused by B. cinerea or A. alternata, and natural infection. The combination of C. laurentii and UV-C showed better control efficiency. UV-C treatment did not affect yeast growth in fruit wounds, while the treatment induced the transcript expression of beta-1,3-glucanase, phenylalanine ammonia-lyase, peroxidase and superoxide dismutase based on real-time PCR analysis, as well as increased the activity of these enzymes in tomato fruit. Results indicate that the mechanism by which UV-C enhanced the biocontrol efficacy of C. laurentii may be associated with the elicitation of defense response in tomato fruit.