Prevalence of mango stem-end rot disease in Côte d'Ivoire and identification of associated fungal pathogens

Abstract

The Stem-end rot (SER) postharvest disease of mango (Mangifera indica L.) fruits is a significant economic threat to mango production. Without proper management strategies, it can lead to up to 100 % postharvest losses. Despite its importance, very little information is known about this disease in Côte d'Ivoire. This research aimed to determine the incidence and severity of SER in mango orchards, assess how preharvest climate parameters affect the disease and determine the pathogenic fungi associated with SER. Mango SER was evaluated on 1500 mango fruits collected from 15 orchards in Boundiali, Ferkéssédougou, Korhogo, Odienné, and Sinématiali departments. Mango SER incidence ranged from 10 % to 30 %, while severity ranged from 5 % to 20 %. No significant differences in these parameters were observed between the different departments (P>0.05). The study also revealed a positive low correlation between SER disease incidence and mean air temperature (r = 0.36) and minimum air temperature (r = 0.26) data, indicating that preharvest weather conditions may have a marginal impact on mango SER disease intensity in the postharvest phase. Pathogenic fungi associated with SER were isolated and identified using morphological characteristics and multilocus sequence analysis of the rDNA internal transcribed spacer (ITS) region and the translation elongation factor 1-alpha (tef1-α). Various fungal species associated with mango SER disease were also identified, with Lasiodiplodia species (74%) being the most prevalent (including Lasiodiplodia theobromae, L. euphorbicola, and L. caatinguensis), followed by Colletotrichum gloeosporioides, Curvularia pseudobrachyspora, Diaporthe endophytica and Fusarium mangiferae. However, only Lasiodiplodia species and Diaporthe endophytica induced SER symptoms. This study was the first ever evaluation of mango SER disease and associated fungal pathogens identification in Côte d'Ivoire. This result will assist researchers in developing a control method for mango SER.