Antagonism of fungi with biocontrol potential of papaya black spot caused by Asperisporium caricae

Abstract

The antifungal activity of fungi with biocontrol potentials should be studied. Therefore, this study aimed at establishing alternative agent to replace the chemical control of papaya black spot. We investigated the antagonistic activity of the fungi Hansfordia pulvinata (H-611), Acremonium sp (A-602, A-617 and A-598), Simplicillium lanosoniveum (S-599), Lecanicillium lecanii (L-622), and Sarocladium implicatum (I-609) on the phytopathogenic fungus A. caricae, by evaluating the mycoparasitism, the enzymatic activity and the production of volatile and non-volatile compounds. For the evaluation of mycoparasitism, each antagonic fungi isolate was microcultured along with conidia of A. caricae. Then, events of mycoparasitism were evaluated at 24h, 48h, 72h, and 96h after inoculation under an optical microscope. We estimated the enzymatic activity (protease and lipase) of the fungi in a particular culture medium for each enzyme. The activity of the protease was reflected in the mean diameter of the halo. The lipase activity was measured by the halo/colony relation. In order to detect volatile compounds in the antibiosis test, A. caricae was cultured under a medium along with the isolates described. For the test of non-volatile compounds, we evaluated the germination of A. caricae in culture medium by diffusion under cellophane paper. As a result, the mycoparasitism of the H-611, A-602, A-617, A-598, S-599, and L-622 isolates was confirmed on the microcultures. We observed higher activities of protease in the I-609, S-599, A-602, and A-598 isolates. The H-611 and A-602 isolates presented higher activities for lipase. We did not observe effect of volatile compounds in any of the tested isolates. In the non-volatile compound test, there was production of antifungal metabolite highlighting the A-617 isolate, which inhibited the germination of the conidia of A. cariae by 100%.

Fungal Endophytic Community Associated with Guarana (Paullinia cupana Var. Sorbilis): Diversity Driver by Genotypes in the Centre of Origin

“…6.21 reported in [ 83 , 84 ] have antagonistic activity against phytopathogens through mycoparasitism and the production of secondary metabolites that aid in the breakdown and degradation of the cell wall. Another mycoparasite species, also found in guarana, is Simplicillium lanosoniveum S-599 which parasites fungi by secreting proteases [ 85 ].…”

Rhizospheric Fungi to Plant Growth Promotion: A Review

“…However, it is necessary to study other species with potential antagonists against phytopathogens. In this sense, Vivas et al (2018) demonstrates in his study the potential application of other species of filamentous fungi in the control of phytopathogenic fungi, highlighting the genera Acremonium and Sarocladium. As Köhl et al (2019) that studying antagonistic candidates talk about the genera Aspergillus and Cladosporium, which demonstrates that the species should be studied further, especially when it comes to the production of potentially inhibitory metabolites to phytopathogenic fungi.…”

“…Beneficial microorganisms such as actinomycetes, common bacteria and filamentous fungi have been studied for agricultural development, making it possible to use their functions to develop processes. The action of the soil microbiota provides benefits such as biological N fixation, phosphate solubilization and biological control of phytopathogens and agricultural pests, which has already been demonstrated in previous studies (Yuan et al, 2010;Silva et al, 2017;Vivas et al, 2018). In this sense, this systematic review sought to address the main mechanisms for promoting plant growth through the action of soil and/or rhizospheric fungi.…”

Sensitivity of hyperparasitic fungi to alternative products for use in the control of papaya black spot

“…The biological control is, in turn, a possibility that has been studied for papaya trees (Vivas et al, 2015(Vivas et al, , 2018. This measure consists of using an antagonistic organism, which reduces the multiplication or survival of the pathogen, resulting in the control of the disease.…”