Reaction to common root rot of 14 Triticum species and the incidence of Bipolaris sorokiniana and Fusarium spp. in subcrown internode tissue

Abstract

There was wide variation in the common root rot reaction of lines and varieties of 14 Triticum species. The diploids, T. aegilopoides and T. monococcum, were the most resistant. Triticum timopheevi appeared to be more resistant than the other tetraploid species. The highest disease ratings were recorded in the hexaploid group with T. compactum being the most susceptible species. The range of reaction within the T. aestivum group was almost as wide as that over all Triticum species. Several old varieties appeared to have resistance at least equal to Manitou. Bipolaris sorokiniana was isolated from subcrown internodes of all lines and varieties tested. The incidence of B. sorokiniana in tetraploid and hexaploid lines was about twice that found in diploid lines. There were only poor correlations between disease ratings and numbers of internodes yielding B. sorokiniana.