Molecular characterization of Beauveria bassiana Isolated Central Control of Coffee Berry Borer

Abstract

The most important pest for coffee crops in Honduras is the berry borer Hypothenemus hampei. Beauveria bassiana is a fungus used in biological control of this insect. Local fungi isolates have been evaluated in a traditional way, but they haven´t been characterized genetically in order to establish the relationship between isolates and its pathogenicity. Our study explored the potential application of genetic diversity of Central American B. bassiana isolates using Intermicrosatellite markers, SSR sequences and ITS. These isolates were also analyzed by their infectivity under laboratory and field conditions. All the isolates obtained from the Central American region show low genetic diversity and there were not significant differences in their infective capabilities over the coffee berry borer.

Besides that, BB-XN had a better performance as a pathogen both in laboratory as in field conditions. Although it was not possible to distinguish the isolates by the ITS approach, we found three ISSR primers which alone could distinguish all the Central American isolates. Through these markers is possible to distinguish the identity of each isolate. The sequence analysis of SSR produced a dendrogram with exactly the same structure than the tree obtained from the amplifications with ISSR. Therefore SSR sequences are as reliable as the analysis of ISSR in order to establish phylogenetic relationships between isolates. In conclusion, we have optimized a set of markers in order to determine variability of regional Beauveria´s isolates and this is the first step to apply them for distinguishing between genotypes and its commercialization.

DOI: http://dx.doi.org/10.5377/rct.v0i8.699

Revista Ciencia y Tecnología, No. 8, junio 2011 pp.39-61