An improved synthetic medium for oospore production and germination of several Phytophthora species

Growth of Phytophthora arecae, P. cactorum, P. cambivora, P. capsici, P. cinnamomi, P. citricola, P. citrophthora, P. colocasiae, P. cryptogea, P. drechsleri, P. erythroseptica, P. fragariae, P. heveae, P. lateralis, P. meadii, P. megasperma, P. megasperma var. sojae, P. palmivora, P. parasitica, and P. syringae on a chemically defined medium was comparable to that on a V-8 juice agar medium. A majority of the species produced oospores on the synthetic medium. Oospores were also produced by the interspecific hybrids, P. capsici (A1) X P. parasitica (A2), P. capsici (A1) X P. palmivora (A2), P. cinnamomi (A1) X P. cambivora (A2), P. cinnamomi (A1) X P. drechsleri (A2), and P. parasitica (A1) X P. citrophthora (A2). Germination of oospores obtained from the synthetic medium was comparable to, or better than that observed for oospores produced on V-8 juice agar medium.