Development of methods using phytoalexin (resveratrol) assessment as a selection criterion to screen grapevine in vitro cultures for resistance to grey mould (Botrytis cinerea)

Summary The purpose of this research was, firstly to determine the ability of grapevine in vitro cultures to synthesize resveratrol, a stilbene-type phytoalexin that is considered to be a good marker for resistance of grapevines to Botrytis cinerea, the causal organism for grey mould. Secondly, this study sought to establish the relationship between phytoalexin production potential and resistance to Botrytis cinerea in grapevines. In this aim, resveratrol production was assessed in 13 Vitis species or cultivars. A good correlation appeared between resveratrol production by grapevine in vitro cultures and grey mould resistance except for two Vitis spp. for which no correlation was observed, thus suggesting that resistance of grapevines may sometimes be associated with factors other than stilbene phytoalexins. In view of the results obtained, the potential use of resveratrol induction and of in vitro methods as a tool for screening grapevines for resistance to B. cinerea was discussed.