EFFECT OF SALICYLIC ACID AND METHYL JASMONATE ON Colletotrichum sp. IN MANGO FRUITS

Abstract

Background: mango anthracnose, caused by Colletotrichum gloeosporioides, is the main mango disease in pre and post-harvest. Mainly synthetic fungicides have been used in its management, which has negatively impacted the environment and the health of workers. The induction of resistance in fruits by biological, physical or chemical means is considered a sustainable and safe strategy for the management of post-harvest diseases of fruits and vegetables. Methyl jasmonate (MeJa) and salicylic acid (AS) are natural and safe compounds that represent a promising alternative in post-harvest control. Objectives: to determine the effect of MeJa and AS on mycelial growth and spore germination of Colletotrichum sp., under in vitro conditions, and to evaluate the effect on development of postharvest damage caused by the pathogen in mango fruits treated with MeJa and AS. Methodology: the activity of MeJa and AS in the germination of spores and the mycelial growth of Colletotrichum sp., were evaluated in culture medium Broth Papa Dextrose and Papa Dextrose Agar, respectively. Healthy mango fruits were treated by immersion with MeJa and AS solutions at 1 and 10 mM for 5 min, and 24 h later they were inoculated with Colletotrichum sp., to evaluate the effect on the diameter of the lesion caused by the fungus to the 6 and 12 days after inoculation (dai). Results: MeJa and AS inhibited the germination of Colletotrichum sp., spores after 24 hours of incubation in vitro, while the mycelial growth of the fungus in PDA medium, 1 and 10 mM of MeJa and AS, showed significant reductions in growth in comparison to control. In fruits, it was observed that the 10 mM MeJA and AS treatments significantly reduced the diameter of the lesion caused by the fungus, compared to the control fruits at 12 dai. Implications: future trials should evaluate other concentrations of MeJa and AS in other mango varieties to assess the response to anthracnose. Conclusions: MeJa and AS inhibited spore germination and mycelial growth of Colletotrichu sp., under in vitro conditions, while in mango fruits these inducers significantly reduced the diameter of the lesion caused by this fungus, which suggests that both products can reduce the damage caused by Colletotrichum sp., in mango fruits.