Elicitation and accumulation of stilbene phytoalexins in grapevine berries infected by Botrytis cinerea

At three developmental stages berries of field-grown Castor (interspecific crossing) and Huxelrebe (V. vinifera L. crossing) were in vitro inoculated with two strains of Botrytis cinerea Pers. to investigate the response of berries to fungal infection With respect to the time course of phytoalexin (trans-resveratrol, ε-viniferin and pterostilbene) accumulation and Visual disease symptoms. In infected berries the amounts of ε-viniferin dominated over pterostilbene. The stilbene phytoalexin content decreased during berry development and sugar accumulation. Grape varieties reacted differently to B. cinerea strains with regard to stilbene response and Visual symptoms. Mechanical damage of the berry skin induced uninfected berries to synthesize low amounts of phytoalexins. It can be assumed that after extraction and degradation ε-viniferin of mature berries is a source of resveratrol in wine