Pg. 51-57 ldentification of Penicillium species in the litchi export chain

Penicillium species can cause major losses to the fruit export industry, as post-harvest decay of litchi fruit by this genus dramatically reduces the shelf life of the fruit. This study was aimed at identifying the most dominant Penicillium species throughout the litchi export chain and drawing comparisons between local and international isolates. From this study, several critical control points affecting cross-contamination of litchi fruit during export were identified. Morphological, as well as molecular methods such as PCR-RFLP were used in the identification of these Penicillium species. Thirteen of the most dominant Penicillium species isolated during the 2004/05 season were identified as P
expansum, P griseofulvum, P spinulosum, P brevicompactum, P corylophilum, P verrucosum, P aurantiogriseum, P sclerotiorum, P glabrum, P solitum, P citrinum, P chrysogenum and P crustosum. Penicillium expansum was the most dominant species isolated in this study. Penicillium citrinum was only isolated locally, which may indicate that this species does not affect the quality and safety of the fruit during export. These 15 groups were divided into four molecular-based groups, through PCRRFLP. Future research will involve the investigation of alternative gene regions, which may identify appropriate restriction enzymes to differentiate between these Penicillium species.