Bacterial volatile mediated suppression of postharvest anthracnose and quality enhancement in mango

Abstract

Anthracnose disease incited by Colletotrichum gloeosporioides reduces the yield and market-quality of mangoes worldwide. Previous studies have indicated the potential of diverse antimicrobial volatile organic compounds emitted by the endophytic Pseudomonas putida BP25 for plant disease suppression. In the present study, we have explored native-volatiles of Pseudomonas putida BP25 and a synthetic-volatile, 2-ethyl-5-methylpyrazine, earlier identified in volatilome of Pseudomonas putida BP25 for reducing anthracnose in mango cultivar, Amrapali. The bacterial volatile compounds displayed fungistatic effects on the mycelial growth of Colletotrichum gloeosporioides in vitro. In planta prophylactic fumigation of mangoes with native-volatiles or the bacterial origin synthetic 2-ethyl-5-methylpyrazine for 24 h at 25 °C showed a reduction of anthracnose severity (>76 % reduction over mock) on fruit. Additionally, physicochemical qualities such as total-soluble solids, total-phenols, total-proline, total-carotenoid, total-flavonoid, and fruit-firmness were increased in fumigated fruit as compared to untreated mangoes. Anthracnose suppression coupled with the fruit quality enhancement by bacterial volatiles and synthetic 2-ethyl-5-methylpyrazine presents a new opportunity for postharvest management of mango during the storage, transit, and trade.