DETERMINACION DE ALELOS DE COMPATIBILIDAD SEXUAL EN POBLACIONES DE Mycosphaerella graminicola DE ARGENTINA

ALBANI C. M.; CONSOLO V. F.; SALERNO G. L.; CORDO C. A.

Congreso; XIII Congreso Latinoamericano de Fitopatología.; 2005

Mycosphaerella graminicola (Fuckel) J. Schroter in Cohn causes leaf blotch, which is the major worldwide wheat disease. Populations of the pathogen present high degree of genotype diversity, even on a very local scale. Asexual reproduction has an important impact over a small area but sexual reproduction has much greater consequences for the population genetics and biology. Like other Ascomycetes, sexual reproduction in M. graminicola is determined by the presence of two alleles at a single mating-type locus designated MAT1.1 and MAT1.2, which have been cloned and sequenced. Two types of isolates, each one harboring MAT1.1 and MAT1.2 locus are required for the completion of sexual reproduction. The role of mating in structuring populations of phytopathogenic fungi and how mating is related to pathogenicity are research areas that are gaining increasing interest. Detailed knowledge of mating-type genes, as controllers of reproductive process is of importance to understand the evolution of sexuality in fungi. Isolates of M. graminicola from bread wheat were collected between 1998 and 2000 from Barrow and Los Hornos Experimental Stations in Argentina and analyzed for mating distribution. Each isolate was tested for mating type through a multiplex polymerase-chain-reaction based assay. Both alleles were identified in each population, which suggests that sexual reproduction may be playing a major role in M. graminicola population structure in the sampled locations. Financiamiento: CONICET- FIBA.