Dr Mereia Fong Lomavatu1,3, S J R Underhill1, Dr Lindy Coates2, Mr Tony Cooke2, K Chandra2
1University of the Sunshine Coast, Maroochydore DC, Australia, 2Department of Agriculture and Fisheries, Eco Science Precinct, Dutton Park, Australia, 3Ministry of Agriculture, Koronivia Research Station, Nausori, Fiji
Colletotrichum sp. is the only postharvest pathogen recorded in Fiji’s pest list database for mango (Vernon, 2003). Effective disease management strategies can only be developed and deployed if pathogens are known. Absence of good postharvest disease management, poor mango fruit quality and reduced shelf-life will undermine market demand, limit small holder profitability and add further challenges to export and market development.
The objective of the study was to determine the presence of postharvest diseases of mango in Fiji. Over two mango seasons, postharvest disease assessments were conducted on mango fruits obtained from five local Fijian cultivars from five major production localities and from five exotic cultivars at one locality. Fruits were cleaned, placed in ripening boxes and stored in the laboratory where the temperature was set at 23±2°C. At eating ripe stage, diseased fruits were isolated and subcultured on fresh ½ strength PDA plates amended with streptomycin (SPDA, 20g Difco™ potato dextrose agar powder plus 20ppm streptomycin, dissolved in 1 L distilled water and autoclaved). Genomic DNA was extracted using the BioSprint 15 (QIAGEN) according to the manufacturer’s instructions. 122 isolates out of the total of 126 isolates sequenced (96.8%) were identified as C. asianum using ITS primers. Although the ITS region is known to reliably differentiate C. asianum from other Colletotrichum species (Weir et al., 2012). It was decided to sequence a subset of 30 putative C. asianum isolates at the BT and CAL regions to confirm their identity. While C. asianum was identified as the predominant fungus isolated in association with mango anthracnose in Fiji, C. simmondsii and C. fructicola using ITS, BT and CAL were also found.
- Vernon, R., 2003. The Pacific pest list database for agricultural trade facilitation. EPPO Bulletin 33, 501-504.
- Weir, B.S., Johnston, P.R., Damm, U., 2012. The Colletotrichum gloeosporioides species complex. Studies in Mycology 73, 115-180.
Dr. Mereia Fong-Lomavatu is currently the Principal research Officer, Plant Protection with the Ministry of Agriculture in Fiji based at the Koronivia Research Station. She is a Plant Pathologist working on postharvest diseases of fruits, Chilli anthracnose and general pathogen diagnosis work and is also the Pesticide Registrar for Fiji. This work was part of her research while doing her PhD at the University of the Sunshine Coast, QLD while she was based at the EcoScience Precinct, Dutton Park in Brisbane work with Dr Lindy Coates and her Fruit Pathology team.