Response of endemic <em>Mangifera zeylanica</em> (Blume) Hook. f. fruit to common postharvest pathogens of cultivated mango (<em>Mangifera indica</em> L.) fruit in Sri Lanka

Abstract

Two species of Mangifera are found in Sri Lanka, the cultivated Mangifera indica L. and the endemic M. zeylanica (Blume) Hook.f. [Et-amba (S)]. Mangifera indica is a climacteric fruit, susceptible to infection by many fungal pathogens, causing postharvest diseases at ripe stage. Among them, Colletotrichum spp. and Lasiodiplodia theobromae that cause anthracnose and stem-end rot disease respectively, are considered the most destructive postharvest pathogens in ripe mangoes. Harvested fruit of M. zeylanica also showed a climacteric pattern of respiration and the pulp was sweet to taste, with acceptable TSS value for mango fruit. The present study investigated the resistance or susceptibility of the fruit of endemic M. zeylanica to these two pathogens. Artificial inoculation of fruits with C. gloeosporioides and L. theobromae separately, produced anthracnose as well as stem-end rot symptoms respectively, showing that M. zeylanica fruits are susceptible to the pathogens. However, considering the pattern and the extent of disease development, M. zeylanica fruits can be considered moderately resistant to both pathogens. Alternaria sp., Pestalotiopsis sp., Lasiodiplodia theobromae, Curvularia sp. and Neofusicoccum sp. were frequently isolated from the pedicel and the stem-end region of healthy fruits of M. zeylanica at harvesting maturity. However, Colletotrichum species could not be isolated from either the pedicel or the stem-end region of M. zeylanica. TLC-Cladosporium bioassay of peel extract of the unripe M. zeylanica fruit resulted in a large inhibition zone at Rf 0.00 which corresponded with antifungal gallotannins contributing to the constitutive defences of M. indica fruit against invading pathogens.

Keywords

• mangifera zeylanica, endemic, postharvest, anthracnose, stem-end rot, mango fruit