RAPD e ITS detectan variación molecular en poblaciones Chilenea de Beauveria bassiana

Abstract

Entomopathogenic fungi are an attractive alternative for the biological control of insects. In Chile, the Quilamapu Regional Research Center of the National Agricultural Research Institute (INIA) has collected about 400 isolates of the genus Beauveria along the country. A partial classification of this collection has been based on morphology and efficiency as biological control agents. It is necessary to complement this characterization with genetic molecular markers, to determine the level of genetic diversity in Chilean Beauveria bassiana populations and to identify banding patterns that discriminate among isolates from a representative sample of the B. bassiana collection. The analysis was done using Random Amplified Polymorphic DNA (RAPD) and Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) of Internal Transcribed Spacer (ITS)-rDNA sequences. The RAPD analysis indicated high genetic diversity among the isolates, with a 43% of similarity on the average. RAPD were more efficient at identifying isolates. On the other hand, the ITS analysis determined a lower diversity, with an 83% of similarity among the isolates. The low number of haplotypes did not allow discrimination among isolates. ITS 1 region showed a higher number of restriction sites, compared to ITS 2 region. For the two molecular markers, genetic diversity was not associated with the geographical origin of the isolates. © 2007 Instituto de Investigaciones Agropecuarias, INIA.