Identification of two genes for resistance to Triticum isolates of Magnaporthe oryzae in wheat.

A screening of common wheat cultivars revealed that Triticum aestivum 'Thatcher' was resistant to Triticum isolates of Magnaporthe oryzae, whereas T. aestivum 'Chinese Spring' was susceptible. When F2 seedlings from a cross between 'Thatcher' and 'Chinese Spring' were inoculated with the Triticum isolates, resistant and susceptible seedlings segregated in a 15:1 ratio, suggesting that the resistance of 'Thatcher' was conditioned by two major genes. An inoculation test of 'Chinese Spring' substitution lines carrying individual chromosomes from 'Thatcher' indicated that these genes, designated Rmg2 and Rmg3, were located on chromosomes 7A and 6B.