Identification and molecular phylogenetics of lasiodiplodia parva associated with white, yam (dioscorea rotundata L.) in Ghana

Abstract

Ten isolates of the fungus obtained from diseased yam tubers were identified using morphological characterisation, complemented with phylogenetic study, involving sequences of the rDNA-ITS region and part of the beta-tubulin gene of isolates. The pathogenicity of the isolates was tested on healthy yam tubers. The conidial morphology and size indicated that the isolates were Lasiodiplodia parva. In the phylogram, the isolates clustered with the type strain of L. parva and other L. parva strains of confirmed identities, in clade supported by a high bootstrap value. The fungus was able to cause the disease symptoms on artificially inoculated tubers, showing that it was responsible for the disease symptoms. The results showed that L. parva was responsible for the hard rot disease of yam in storage in Ghana, rather than the L. theobromae cited in the literature.