Infection pathway of the stem end rot fungus Dothiorella dominicana in 'Kensington' mango fruit.
Gosbee M. J., Johnson G. I., Joyce D. C.
Author Affiliation: CRC for Tropical Plant Pathology, University of Queensland, St Lucia, Qld. 4072, Australia.
: 595-599
Abstract : D. dominicana is one of several pathogens causing stem end rot of mangoes in Australia and other countries. D. dominicana was recovered after triple sterilization from symptomless seedlings grown from infected fruits, suggesting endophytism. Kensington mangoes obtained from the Northern Territory, Australia, were inoculated with D. dominicana. Superficial quiescent infections were controlled by hot water dipping. Fruits were surface sterilized and isolations made from 18 points in the fruits and seeds at 0, 1, 2, 4, 6, 8 and 11 days after inoculation. Uninoculated controls were assayed on days 0, 4, 8 and 11. The fungi grew down the vascular tissue into the peduncle (day 2), pedicel (day 4), and under the skin (day 6). Colonization preceded lesion development, which began on day 8. The seed was infected firstly through the funiculus (day 6), endocarp and testa (day 8), then into the embryo (day 8-11) where it caused decay. Seedlings grown from inoculated fruits showed the highest recovery of D. dominicana in the connective tissue between the embryo and seedling and the hypocotyl zone.