Abstract
Pseudopyrenochaeta lycopersici is a soil-borne fungus causing corky root of tomato. The slow growth and poor sporulation of the pathogen make its isolation difficult. Isolates of the fungus are classified into types 1 and 2, with many different physiological and molecular characteristics between both types. In general, mating type genes enable mating ability and sexual development. The type 1 strains CBS267.59 and Oha3-6 of P. lycopersici were utilized to amplify DNA binding domains (HMG box). The MAT1-1-1 gene of CBS267.59 encodes a predicted protein including an alpha box DNA binding domain, while MAT1-2-1 of Oha3-6 encodes a predicted protein including an HMG DNA binding domain. The sequences of the putative P. lycopersici alpha and HMG boxes were very similar to established alpha and HMG boxes. ORF1 and the DNA lyase gene were found in the 5MODIFIER LETTER PRIME and 3MODIFIER LETTER PRIME regions, respectively, of the MAT1-1 locus. Comparison of the mating type genes and flanking regions was carried out between the strains CBS267.59 and Oha3-6 and other Loculoascomycetes, Pyrenomycetes and Discomycetes. The assembled sequences were 2932 bp (nucleotide positions 426-3358) for the MAT1-1 idiomorph and 3410 bp (nucleotide positions 438-3848) for the MAT1-2 idiomorph. Multiplex polymerase chain reaction amplified 432 bp and 786 bp bands in the MAT1-1 and MAT1-2 strains, respectively. The isolation and characterization of the MAT genes of P. lycopersici improve our knowledge and may help to explain the taxonomic differences in types 1 and 2 of this fungus.