Phytophthora cryptogea causing the foot rot of Gerbera jamesonii in Korea.
Since 1992, a destructive foot rot of gerbera caused by a Phytophthora species has occurred in most cultivation areas in Korea Republic. Infected plants showed symptoms of wilting due to decay of the main rooting system which led to their eventual death. A total of 47 isolates were collected from roots and petioles of infected plants and identified as P. cryptogea based on morphological, cultural and physiological characteristics. Among 20 isolates tested, sexual types A1 and A2 numbered 8 and 4, respectively, the remaining 8 isolates were sterile. In pathogenicity tests, none of the 7 gerbera cultivars grown in Korea Republic were resistant to the disease. P. cryptogea has not been reported as a causal pathogen of foot rot of gerbera or any other hosts in Korea Republic previously.