Submitted to: Mycoscience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/25/2000
Publication Date: N/A
Interpretive Summary: The genus Fusarium contains many plant pathogens and toxin-producing species. Of these, Fusarium verticillioides has a worldwide distribution but has never been reported from Japan. However, during a routine plant quarantine inspection, over 10 tons of rotten banana fruits imported from Mexico were intercepted in Kobe, Japan. Subsequently the banana pathogen was demonstrated to be F. verticillioides. This determination was based on detailed examination of their microscopic anatomy and molecular genetic data in the form of DNA sequences from two genes. When pathogenicity tests were conducted by inoculating the banana strains onto banana, corn and soybean, the strains were only strongly pathogenic to banana. Detailed microscopic examination of the banana strains revealed that they are slightly atypical of F. verticillioides in that they regularly produce chains of spores that are divided by a septum. F. verticillioides, in contrast, rarely produces such spores. Features of this unique post- harvest disease are discussed.
Technical Abstract: Seven strains of Fusarium were isolated from rotten fruit of banana (Musa cavendishii) imported into Japan from Mazanilo, Colima, Mexico. Morphological features of the isolates were described and illustrated, and their pathogenicity to banana was determined. Morphological and molecular phylogenetic analyses revealed that these isolates were conspecific with F. verticillioides. However, constant production of septate aerial conidia in chains by the banana isolates distinguished these strains from previous descriptions of this species. Morphological examination of the isolates revealed that they are consistent with Wollenweber's original concept of F. moniliforme var. minus. The effect of black light illumination on conidial production by these isolates was also tested.