Persistence of Brazilian isolates of the entomopathogenic fungi Metarhizium anisopliae and M. robertsii in strawberry crop soil after soil drench application

Establishment, persistence and local dispersal of the entomopathogenic fungi Metarhizium anisopliae (ESALQ1037) and M. robertsii (ESALQ1426) (Ascomycota: Hypocreales) were investigated in the soil and rhizosphere following soil drench application in strawberries between 2012 and 2013 at a single location in Inconfidentes, Minas Gerais, Brazil. Metarhizium spp. isolates (n = 108) were collected using selective agar media and insect bait methods, and characterized by sequence analyses of the 5'-end of the translation elongation factor 1-α and the MzFG543igs intergenic region and by multilocus simple sequence repeat analysis. Both applied fungal isolates were frequently recovered from bulk soil and rhizosphere samples of the treated plots, suggesting that they were able to establish and disperse within the soil. Persistence within the soil and strawberry rhizosphere for both fungal isolates was observed up to 12 months after application with frequencies of 25% of haplotypes similar to isolate ESALQ1037 and 87.5% of haplotypes similar to isolate ESALQ1426, respectively. Overall, M. robertsii was the most abundant species in the agroecosystem studied representing 77.8% of the isolates recovered across all sample dates.