Inhibition of mycelial growth and conidium germination of Colletotrichum sp. for organic and inorganic products

Abstract

Objective: To evaluate the effect of hydrogen peroxide, potassium sorbate, sodium bicarbonate, and chitosan on mycelial growth and in vitro germination of Colletotrichum sp., to be used for future management of anthracnose disease in postharvest cv. Ataulfo mango fruit. Design/Methodology/Approach: The effectiveness of the treatments was evaluated using the poisoned culture method. The evaluated concentrations of hydrogen peroxide and potassium sorbate were 1.0, 0.8, 0.6, 0.4, 0.2, 0.16, 0.12, 0.08, and 0.04 %; sodium bicarbonate, 1.0, 0.8, 0.6, 0.4 and 0.2 %; and chitosan, 2.5, 2.0, 1.5, 1.0 and 0.5 %. A 6-day disk of Colletotrichum sp. mycelial growth was placed in each poisoned culture medium. The inhibition of mycelial growth and the germination of Colletotrichum sp. conidia were evaluated. The experimental design was completely randomized with five repetitions for mycelial growth and four for conidium germination. The results were analyzed using the Kruskal-Wallis test and the comparison of average ranges. The CE50 and CE95 of each product was estimated using Probit analysis with the results of mycelial growth inhibition. Results: The mycelial growth inhibition (100%) of the Colletotrichum sp. strain was reached starting at concentrations of 0.16, 0.2, 1.0, and 2.5% for hydrogen peroxide, potassium sorbate, sodium bicarbonate, and chitosan, respectively. The inhibition of conidium germination was only observed in treatments with hydrogen peroxide and potassium sorbate. The CE50 and CE95 for hydrogen peroxide was 0.1 and 0.12%; for potassium sorbate, 0.10 and 0.19%; for sodium bicarbonate, 0.16 and 0.88%; and for chitosan, 1.20 and 2.18%. Findings/Conclusions: The evaluated treatments represent an effective and viable ecological alternative for the control of Colletotrichum sp., causal agent of anthracnosis in mango fruit.

Control de Colletotrichum “agente causal de la antracnosis en el fruto del mango (Mangifera indica L.)” aplicando metabolitos de Trichoderma

“…en el fruto del mango En placas Petri estériles de 60 x 15 mm, sin medio de cultivo, se depositó por separado 1000 µl de solución de metabolitos de T. harzianum y T. viride, y 50 μl de una suspensión de 10⁵ conidias ml -¹ de Colletotrichum. Las placas se incubaron a 25 °C, durante 24 horas; con ayuda de un microscopio Leica DM750, se contaron 100 conidias entre germinadas y no para la determinación del porcentaje de germinación de conidias (Gálvez-Marroquín et al, 2022). La conidia se consideró germinada cuando su tubo germinativo tuvo al menos 2 veces el diámetro mayor de la conidia.…”

“…es un porcentaje significativo, considerando que es un valor muy por encima de 50% (Savin-Molina et al, 2021), de 35.07% (Ayón et al, 2020), que se encontró contra Colletotrichum gloeosporioides, y cercano a 87.6% contra Colletotricum sp. (Morales et al, 2020), y 78.3% contra Colletotrichum gloeosporioides (López et al, 2022).…”

“…El control de las lesiones de antracnosis de Colletotrichum en el fruto del mango por la solución de metabolitos de T. harzianum (<50%) y T. viride (55.9%), estadísticamente diferentes, corroboran la capacidad fungicida que tienen estos Trichoderma. En la que T. viride, con mayor capacidad controladora, estadísticamente similar al del fungicida TEBUCONAZOL (64.6 %), tuvo un valor ligeramente mayor al de 57 % ejercido por extractos de T. piluliferum que inhibieron el crecimiento de Colletotrichum museau en banano (Costa et al, 2021); en la que T. harzianum con menor capacidad controladora tuvo un valor menor al de 90 % a más, ejercido por suspensión de conidios de T. harzianum que inhibieron el crecimiento de Colletotrichum gloeosporioides en frutos de aguacuate (López et al, 2022).…”