IDENTIFICATION OF THE CAUSAL AGENT OF COCOYAM ROOT ROT DISEASE IN CAMEROON
喀麦隆芋艿根腐病病原菌鉴定

In Cameroon, cocoyam (Xanthosoma maffafa) is one of main edible cro ps cherished for their young leaves and tubers. The production of cocoyam has been decreasing for some years due to the root rot disease. The fungal strains were isolated from field soil and cocoyam roots collected from different areas in Cameroon. The cocoyam plantlets raised axenically from tissue culture and the transplanted pot plants were used for the pathogenicity test in growth chamber. Leaf yellowing and root rotting developed after artificial inoculation with the Pythium isolates XPMY and XPMM1. The isolates were identified as Pythium myriotylum by the mor- phological and physiological criteria. No symptoms of the disease were noted on cocoyam plants inoculated with Fusarium solani and Rhizoctonia solani which were often found associated with Pythium myriotylum. It is suggested that, only Pythium myriotylum is the causal agent of the cocoyam root rot disease in Cameroon.