ASSOCIATION BETWEEN DWARFING GENES RHT1 AND RHT2 AND RESISTANCE TO SEPTORIA-TRITICI BLOTCH IN WINTER-WHEAT (TRITICUM-AESTIVUM L EM THELL)

Differences in levels of resistance to Septoria tritici blotch were observed in plants with a specific height-reducing gene. When the gene 'Rht2' was present either as an isoline or in the progeny, a higher degree of resistance was found. The most susceptible plants were observed in populations carrying the 'Rht1' gene. Associations, as determined by phenotypic correlations, were detected between Septoria tritici blotch and tall stature, late heading, and maturity. Plants having short stature, early heading, early maturity, and acceptable levels of resistance were identified in the F2 population when Rht2 was present. Results of this study indicated that wheat breeders must select the appropriate dwarfing source that may confer resistance and grow large F2 populations, in order to increase the probability of obtaining desired genotypes. © 1990 Springer-Verlag.