Retention of the fruit peduncle at harvest retains sap and contributes to resistance against post-harvest anthracnose disease in 'Kensington Pride', but not in 'R2E2' mango

摘要

'Kensington Pride' mango (Mangifera indica L.) fruit stored with 2 - 3 cm-long peduncles had significantly smaller anthracnose lesion areas after being inoculated with Colletotrichum gloeosporioides at 10(7) spores ml(-1) than fruit that had been desapped and stored according to normal commercial practice. In contrast, lesion development in 'R2E2' mango fruit was not influenced by the presence of the peduncle. 'Kensington Pride' fruit, with their peduncles attached, contained significantly higher levels of 5-n-heptadecenylresorcinol and 5-n-pentadecylresorcinol in their peel compared with desapped fruit. At harvest, 'Kensington Pride' fruit sap contained approx. 61% of the total 5-n-heptadecenylresorcinol and 47% of the total 5-n-pentadecylresorcinol present in the fruit. 'R2E2' fruit sap contained lower concentrations of alk(en)ylresorcinols but, in both mango varieties, retention of the peduncle did not influence fruit ripening. These results suggest that harvesting 'Kensington Pride' mango fruit with a long (2 - 3 cm) peduncle maintained alk(en)ylresorcinol concentrations in the peel and in resin duct sap, and contributed to improved fruit resistance against anthracnose disease. Lower concentrations of sap alk(en)ylresorcinols correlated with weaker resistance to anthracnose in 'R2E2' mango fruit.