Identification and aggressiveness of four isolates of Fusarium oxysporum f.sp. cubense from Latundan banana in Brazil

Abstract

Members of Fusarium oxysporum species complex (FOSC) have been exten-sively studied because it causes many crop diseases and losses. This com-plex has more than 150 putatively plant host-specific formae specialessuch as F. oxysporum f.sp. cubense (Foc), the aetiological agent of Fusariumwilt of banana, Panama disease. The objective of this study was to charac-terize isolates obtained from rhizomes of the latundan (apple) variety ofbanana showing symptoms of Panama disease using morphological mark-ers, phylogenetic analyses of the TEF-1a and pathogenicity tests. Isolateswere harvested from the states of Minas Gerais (Foc GO2), Goias (FocGO1 and Foc GO2A) and Bahia (Foc 807). Morphological markers of iso-lates observed are in accordance with the original descriptions of theF. oxysporum. Foc isolates grouped into two different lineages, and one ofthese is a lineage not yet recorded. Aggressiveness was assessed by a ratingscale of the symptoms displayed in the shoot, rhizome and conductingvessels in latundan banana trees. The results indicated that all isolatesbelong to F. oxysporum f.sp. cubense, race 1. Isolate Foc GO2A proved to bemore aggressive than the others. The results generated in this study con-tribute to knowledge of lineages diversity within Foc