Ferrous Iron and the Growth of Twenty Isolates of Phytophthora Infestans in Synthetic Media

SUMMARY

Twenty isolates of Phytophthora infestans grew well in a D-glucose-L-asparagine medium containing 1.0 ppm of ferric iron provided that 200 mg/liter of L-ascorbic acid were added. Under these conditions ferric iron was reduced to the ferrous state. Most of the isolates reduced ferric iron after variable periods of incubation. Growth in media not containing L-ascorbic acid was associated with the reduction of ferric iron.