First report of mango (Mangifera indica) stem-end rot caused by two Diaporthe species and their susceptibility to procymidone

Abstract

In July 2013, a severe postharvest rot of mango fruits (cv. Lippens), with symptoms identical to stem-end rot caused by Lasiodiplodia theobromae or Neofusicoccum parvum, was found in Okinawa Prefecture, Japan. From affected fruit, Diaporthe species were consistently isolated. The isolates reproduced the original symptoms in healthy mango fruits after inoculation and were re-isolated from the inoculated fruits. Based on morphology and a phylogenetic analysis of rDNA-ITS, CAL, H3, EF1-α, and TUB, the isolates were classified into two Diaporthe species (Clade I and Clade II). In terms of susceptibility to procymidone, a registered fungicide against mango stem-end rot in Japan, the two Diaporthe species were less sensitive than previously reported mango stem-end rot pathogens and had MIC and EC50 values higher than the standard concentration applied.