Natural occurrence of Metarhizium in agricultural avocado soils (Persea americana Mill.) in Colima, Mexico

Abstract

Avocado (Persea americana Mill.) has become one of the most important fruits in the world, being Mexico the main producer and exporter worldwide, it has led to an accelerated growth in the establishment of monoculture avocado plantations, promoting the increase of insect and mite pests, which has led to the need for biological control strategies for integrated pest management. The objective of this study was to isolate entomopathogenic fungi from the soil of a conventional avocado orchard and identify them by translation elongation factor 1-α (5’TEF). During the sampling, a total of 34 isolates were obtained, belonging to the genus Metarhizium, 23 isolates identified as Metarhizium robertsii and 11 as Metarhizium guizhouense. These results show the low diversity of entomopathogenic fungi species associated with the rhizosphere of the avocado crop and suggest that their occurrence could be associated with their ability to survive agronomic practices that induce their endophytic activity. It is necessary to understand the role of Metarhizium in the rhizosphere, this will allow the development of biological control programs specific for each crop, and thus guarantee its success in pest control.