Molecular diversity of the Fusarium fujikuroi species complex from maize

Random amplified polymorphic DNA (RAPD) markers were used to estimate genetic relationship and diversity of Fusarium species associated with pink ear rot of maize. Three Fusarium species – F. verticillioides , F. temperatum and F. subglutinans sensu stricto were collected from contaminated corn kernels. A collection of 41 randomly selected Fusarium isolates (16 F. verticillioides , 16 F. temperatum and nine F. subglutinans sensu stricto) was screened for polymorphism with thirty decamer primers. Seventeen primers that had generated a high number of polymorphic loci were used for the analysis of genetic diversity. The primers yielded a total of 146 polymorphic loci, an average of 8.59 polymorphic bands per primer. The percentage of polymorphic bands (%P) was 46.1%. The RAPD-based UPGMA analysis demonstrated that although F. temperatum and F. subglutinans s.s. form two distinct groups they are more similar to each other than to F. verticillioides. Fusarium verticillioides was the most heterogenous species (Nei’s genetic diversity 0.180), while the least heterogenous one was F. subglutinans s.s. whose genetic diversity was 0.098. The analysis of the translation elongation factor 1-α and β-tubulin gene sequences as well as the mating type ratio were employed to support the RAPD data.