Exploitable regulatory effects of light on growth and development of botrytis cinerea

This research used red, green, blue and white lights to investigate their effects on the growth and development of Botrytis cinerea. Green light suppressed conidial germination and mycelial growth rate of B. cinerea; however, these phenomena were not observed in Alternaria alternata, Fusarium oxysporum and Magnaporthe grisea. Both transmission electron microscopy and laser scanning confocal microscopy demonstrated that the mitochondria damage was most likely to account for the growth inhibition of B. cinerea under green light. Green light also limited the decay development of postharvest grapes and tomatoes infected by B. cinerea, compared to red and blue light and dark treatments. The glucosamine release assay indicated that the mycelial content of B. cinerea-infected grape and tomato tissues were invariably lower in green light-treated groups compared to the other groups. The effects of light on B. cinerea conidiation varied depending on light quality, fungal strains and culturing matrix, with the exception of blue light inhibiting conidiation of all tested B. cinerea strains both in vitro and in the host. In conclusion, the methods to control B. cinerea could benefit from the regulatory effects of artificial light conditions on diverse aspects of the pathogen’s growth and development.