INSTITUTO DE FISIOLOGIA VEGETAL
Unidad Ejecutora - UE
Genetic analysis and comparative virulence of isolates of Pyrenophora
PERELLÓ A.E.; YANNICCARI M; MORENO M. V.; CASTRO A. M.
AFRICAN JOURNAL OF MICROBIOLOGY RESEARCH
Lugar: New York; Año: 2012 vol. 6 p. 5558 - 5558
Tan spot caused by the fungus Pyrenophora tritici-repentis, occurs in many wheat-growing regions worldwide and is considered among the major diseases of wheat in Argentina. In nature, this pathogen reproduces both sexually and asexually, but the extent of genetic variability in the P. tritici-repentis Argentinian population is unknown. The genetic structure of P. tritici-repentis populations was assessed with amplified polymorphic markers with sequence data from the internal transcribed spacer region of the ribosomal deoxyribonucleic acid (DNA) (ITS) analysis. Eighty-nine (89) P. tritici-repentis isolates were collected from 14 geographically distinct regions of the wheat-growing areas in Argentina. Clustered analysis of random amplified polymorphic DNAs (RAPDs) showed seven different groups of isolates at 43% similarity. Analyses of the ITS1 and ITS4 primers grouped the isolates in fifteen separated clusters and resulted in a sensible method by providing valuable information on the genotypic diversity detected in the populations. Additionally, diversity was assayed by analysis of severity and type of symptoms reaction indicating significant differences between cultivars and isolates. The utility of cleaved amplified polymorphic sequence analysis for molecular differentiation of pathotypes was demonstrated. It appears that the P. tritici-repentis population in Argentina is fairly diverse, and caution should be taken in any breeding strategy, since rare pathotypes may quickly become predominant if susceptible host genotypes are continuously grown