Modified agar-based media for culturing Phytophthora infestans

Studies were undertaken to evaluate locally available subtrates for use in a culture medium for Phytophthora infestans (Mont.) de Bary employing a protocol similar to that used for the preparation of rye A agar. Test media preparations were assessed for growth, sporulation, oospore formation, and long-term storage of P. infestans . Media prepared from grains and fresh produce available in Thailand and Asian countries such as black bean (BB), red kidney bean (RKB), black sesame (BSS), sunflower (SFW) and sweet corn supported growth and sporulation of representative isolates compared with rye A, V8 and oat meal media. Oospores were successfully formed on BB and RKB media supplemented with β -sitosterol. The BB, RKB, BSS and SFW media maintained viable fungal cultures with sporulation ability for 8 months, similar to the rye A medium. Three percent and 33% of 135 isolates failed to grow on V8 and SFW media, respectively.