RESUMEN
The elongation factor 1-alpha (EF1-α) and the internal transcribed spacer (ITS) regions ITS1 and ITS2 (ITS1-5.8S-ITS2) sequences were used to characterize and to identify Isaria isolates from Argentina, Mexico, and Brazil, as well as to study the phylogenetic relationships among these isolates and other related fungi from the order Hypocreales. The molecular characterization, which was performed by PCR-RFLP of EF1-α and ITS1-5.8-ITS2 genes, was useful for resolving representative isolates of Isaria fumosorosea, Isaria farinosa, and Isaria tenuipes and to confirm the taxonomic identity of fungi from Argentina, Mexico, and Brazil. The phylogenetic analyses showed three clades corresponding to three families of Hypocreales. The genus Isaria was confirmed as polyphyletic and in family Cordycipitaceae, Isaria species were related to anamorphic species of Beauveria, Lecanicillium, and Simplicillium and to teleomorphic Cordyceps and Torrubiella. Therefore, EF1-α and ITS1-5.8S-ITS2 genes were found to be powerful tools for improving the characterization, identification, and phylogenetic relationship of the Isaria species and other entomopathogenic fungi.
Asunto(s)
Hypocreales/clasificación , Hypocreales/genética , Filogenia , Argentina , Brasil , Análisis por Conglomerados , ADN de Hongos/química , ADN de Hongos/genética , ADN Ribosómico/química , ADN Ribosómico/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Genotipo , Hypocreales/aislamiento & purificación , México , Datos de Secuencia Molecular , Factor 1 de Elongación Peptídica/genética , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , ARN Ribosómico 5.8S/genética , Análisis de Secuencia de ADNRESUMEN
BACKGROUND: Root inoculations of crop plants with beneficial fungi constitute a promising strategy for growth promotion and control of above-ground pests and diseases. Here, strawberry roots (cultivar 'Albion' and 'Pircinque') were inoculated with 25 different Brazilian entomopathogenic fungal isolates of three genera and the effects on Tetranychus urticae oviposition and plant growth were evaluated in greenhouse experiments. RESULTS: Reductions in the number of T. urticae eggs compared to control treatments were observed on both cultivars inoculated with almost all isolates. For the cultivar 'Albion', Metarhizium anisopliae (ESALQ 1604, ESALQ 1669), M. robertsii (ESALQ 1622, ESALQ 1635), Metarhizium sp. Indet. (ESALQ 1684) and Beauveria bassiana (ESALQ 3323) increased dry weight of roots and leaves, and fruit yield, while M. robertsii (ESALQ 1634), Metarhizium sp. Indet. (ESALQ 1637) and (ESALQ 1636) enhanced fruit yield and dry weight of leaves, respectively. For the cultivar 'Pircinque', M. anisopliae (ESALQ 1669) was the only isolate observed to increase dry weight of roots. CONCLUSION: The results suggest that inoculation of strawberry roots with entomopathogenic fungi may be an innovative strategy for pest management above ground. Furthermore, these inoculations may also stimulate plant growth and strawberry production, but the effects depend on fungal strains and crop cultivar. © 2019 Society of Chemical Industry.