| 11055899 |
Dyer PS, Hansen J, Delaney, Lucas JA: Genetic control of resistance to the sterol 14alpha-demethylase inhibitor fungicide prochloraz in the cereal eyespot pathogen Tapesia yallundae. Appl Environ Microbiol. 2000 Nov;66(11):4599-604.
Sexual crosses were used to determine the genetic basis of resistance to the sterol 14 alpha-demethylase inhibitor fungicide prochloraz in the cereal eyespot pathogen Tapesia yallundae. Three different crosses between sensitive parental strains (22-432 and 22-433 [the concentration required to inhibit growth by 50% (IG (50)) for each was PR1 [IG (50) = 1.0 mg/liter], and 11-3-18 [IG (50) = 2.4 mg/liter]) yielded progeny showing a bimodal distribution, with an even number of sensitive and resistant progeny. This indicated the segregation of a single major gene for resistance in each cross, which was confirmed by the use of backcrosses, crosses between F (1) progeny, and control crosses between sensitive parents. However, there was also evidence of additional quantitative genetic components responsible for the increased IG (50) s of the more resistant isolates. A further cross was made between isolate PR11 and an F (1) progeny arising from isolate 11-3-18, and this also yielded progeny which were entirely prochloraz resistant. This suggested that resistance genes were allelic in these two isolates, with resistance conferred by a gene at the same locus (or closely linked loci), despite the fact that the isolates (PR11 and 11-3-18) originated from different continents. |
31(0,1,1,1) |