Mineral Salt Medium for the Growth of Botrytis cinerea in vitro

A mineral salt (MS) medium suitable for culturing Botrytis cinerea in vitro is described. The MS medium contains trisodium citrate, MnSO4, MgSO4, ZnSO4, NH4NO3, KH2PO4, CaCl2, Na2MoO4, vitamin A palmitate, and sucrose. B. cinerea grew vigorously and sporulated numerous conidia in MS agar-medium similarly to those in potato sucrose (PS) agarmedium. The growth was poor if any one of the components in MS medium was omitted. Especially when MgSO4, NH4NO3, KH2PO4 or sucrose was omitted, almost no growth of the mycelium was resulted, suggesting these components appear to be essential. When cucumber leaves were inoculated with the spores suspended in the MS medium the symptom of gray mold rot appeared, but the symptom did not appear when inoculation was made with spores suspended in distilled water. However, the omission of NH4NO3, KH2PO4 or sucrose from the MS medium led to remarkable decrease of infection. A large number of protoplasts with little cell wall debris were isolated by the standard isolation technique6) from 40hr-old mycelium which were cultured in the MS medium. These protoplasts reverted to mycelium at 30-60% after they were incubated in the reversion medium.