Identification of molecular genetic markers in Pyrenophora teres f. teres associated with low virulence on 'Harbin' barley

Two isolates of the barley net blotch pathogen (Pyrenophora teres f. teres) , one possessing high virulence (0-1) and the other possessing low virulenc e (15A) on the barley cultivar Harbin, were crossed and the progeny of the mating were isolated. Conidia from cultures of the parent and progeny isola tes were used as inoculum to determine the inheritance of virulence in the pathogen. Of the 82 progeny tested, 42 exhibited high virulence and 40 exhi bited low virulence on 'Harbin' barley. The data support a model in which a single, major gene controls virulence in P. teres f. teres on this barley cultivar (1:1 ratio; chi(2) = 0.05, P = 0.83). Preparations of DNA were mad e from parental and progeny isolates, and the DNA was subjected to the rand om amplified polymorphic DNA (RAPD) technique in a search for molecular gen etic markers associated with the virulence phenotype. Five RAPD markers wer e obtained that were associated in coupling with low virulence. The data in dicate that the RAPD technique can be used to tag genetic determinants for virulence in P. teres f. teres.