فراوانی تیپ آمیزشی و تنوع نوکلئوتیدی در جدایه های F. verticillioidesبدست آمده از ذرت در برخی استانهای ایران

Fusarium verticillioides is a heterothallic ascomycete causing maize ear, stalk and root rot. In addition to these diseases and its negative impacts on grain yield and quality, F. verticillioides is known to be one of the main agent in the production of harmful mycotoxins, such as fumonisins in corn.The aims of this study were to analyze the genetic variability of 130 F. verticillioides isolates obtained from freshly harvested maize samples (2015 and 2016 harvest seasons) from Khuzestan, Fars, Ardabil and Qazvin provinces of Iran, through mating type determination and phylogenetic analysis based on the sequence RPB2(RNA polymerase II second largest subunit), EF-1α(translation elongation factor 1-α), CaM (Calmodulin), and β-tubulin genes. Moreover, the mating types (MAT-1 and MAT-2) of the isolates were identified by using fusALPHAfor/ fusALPHArev primers which allowed the detection of MAT-1-specific α box and fusHMGfor/fusHMGrev primers for MAT-2-specific HMG box. In order to analyze the phylogenetic sequences obtained from the genetic regions, the Maximum-Parsimony method and the close-neighbor-interchange algorithm were used in Mega software (MEGA4.0). The results showed that 67% of the isolates are MAT2 and 33% are MAT1. Despite the presence of both mating type alleles among the isolates that represents the potential for sexual reproduction and appearance of the genetic diversity, phylogenetic analysis, based on the sequence of the above mentioned genes, revealed low level of nucleotide variability within the F. verticillioides population analyzed. These results can be used for a more appropriated management of maize diseases caused by F.verticillioides. Finally, in order to increase the knowledge on the the genetic diversity of this set of isolates, other genetic markers for their detection are under evaluation and the results of these analyses are ongoing.