Analysis of Iranian isolates of Fusarium solani using morphological, pathogenicity and microsatellite DNA marker characterization

Abstract

Many economically important phytopathogenic species are nested within Fusarium solani species complex. Since most of them lack Latin binomials, morphological and molecular phylogenetic analyses were conducted on strains selected to represent the known pathogenic and genetic diversity of this pathogen. To evaluate methods used in classifying strains of this pathogen, 33 F. solani isolates collected from different geographical regions of Iran, were cultured and characterized using morphology, pathogenicity and microsatellite DNA. All the isolates showed high variability in aerial mycelial growth, mycelia texture, pigmentation (mycelia colour) when cultured on potato dextrose agar medium, and conidial measurements on Spezieller Nahrstoffarmer agar medium. Colonies were grouped into fluffy and fibrous based on mycelial texture; buff, umber, loteous, pale loteous, ochreous and dark brown based on mycelia colour; and long, medium and short macroconidial length. Of the 33 isolates, 26 were pathogenic on Solanum tuberosum, Hordeum vulgare and Cicer arietinum. DNA analysis showed that the isolates showed a high genetic diversity. Ten clusters were reconstructed using microsatellite variation. However, the microsatellite groupings were independent colony characteristics and virulence of the isolates.

Key words: Genetic diversity, simple sequence repeat (SSR) marker, phylogenetic analyses, virulence, Fusarium solani.