|REZENDE, JANAYNE - Brazil University
|ZANARDO, ANA-BEATRIZ - Brazil University
|LOPES, MARIANA DASILVA - Brazil University
|DELALIBRA, ITALO - Brazil University
Submitted to: BioControl
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/30/2015
Publication Date: 2/1/2015
Citation: Rezende, J.M., Zanardo, A.R., Lopes, M., Delalibra, I., Rehner, S.A. 2015. Phylogenetic diversity of Brazilian Metarhizium associated with sugarcane agriculture. Biocontrol. DOI 10.1007/s10526-015-9656-5.
Interpretive Summary: A survey of the insect pathogenic fungus Metarhizium focusing on spittlebug pests in Brazilian agriculture was conducted to determine the indigenous Metarhizium species that naturally cause disease in this group of adult sugarcane pests. DNA sequence analysis of 96 Metarhizium isolated from infected insects and soils assigned these isolates to the M. anisopliae and M. robertsii species lineages. However, only M. anisopliae was isolated from infected insects whereas M. robertsii was isolated only from soil. These results identify M. anisopliae as the most promising candidate for selection and development of biological control strategies to control spittlebug pests in sugarcane agriculture. This information will be used by insect mycologists and plant pathologists researching and iimplementing integrated pest management strategies of field crop pests.
Technical Abstract: Biological control of spittlebug with Metarhizium in sugarcane is an example of the successful application of sustainable pest management in Brazil. However little is known about the richness, distribution and ecology of Metarhizium species in the agroecosystems and natural environments of Brazil. We investigated Metarhizium species in Brazil within a collection of 96 strains isolated from different insect species and soils with a predominance of strains from mycosed spittlebug pests, soil isolates from sugarcane and other agricultural crops, commercial and non-commercial products used for spittlebug biological control as well as soil isolates from pristine habitats. Sequence variation at 5'-TEF and the nuclear intergenic loci MzFG543igs and MzIGS3 were used to assess genotypic diversity and to assign isolates to species and operational taxonomic units. Sequence diversity at these loci included 10, 11 and 17 sequence haplotypes, respectively. Results of a combined phylogenetic analysis of these sequence data yielded robust support for current species limits of the two most abundant taxa, M. anisopliae and M. robertsii, with evidence for phylogenetic subdivisions within these species, and the resolution of two novel lineages outside of currently recognized species limits in this complex. With a single exception, all strains isolated from insects belong to a single subclade of M. anisopliae, including the isolates infecting spittlebugs in sugarcane agroecosystems. Together these data will serve as resources for identification, discovery and communicating about Metarhizium biodiversity for insect biological control applications in Brazil and adjacent countries in South America.