Sweet potato (Ipomoea batatas (L.) Lam.) is the third major staple crop and the second largest economic value in Viet Nam. The wilt and root rot disease, caused by Fusarium solani, is one of the most important problems of sweet potato. The objective of this research was to identify the fungal species causing root rot disease on sweet potato. In this study, the samples were determined based on morphological and pathogenicity. The morphology showed that all 9 strains belonged to Fusarium solani and the conidiophores branch into thin, the macroconidia produced by F. solani are slightly curved, hyaline and broad. Microconidia have thickened basal cells and tapered, rounded apical cells. Fusarium solani also forms chlamydospores most commonly under suboptimal growth conditions are also brown and round. Besides, they induced typical symptoms of root rot disease on sweet potato. The results of this study will be the basis for further researches to find the effective methods to control root rot disease on sweet potato.

Keywords: Fusarium solani, identification, wilt and root rot disease, sweet potato.