Evaluation of take-all resistance in wheat–alien amphiploid and chromosome substitution lines

Abstract

A series of field and controlled environment tests of 'Winalta' – Aegilops squarrosa substitutions for the D genome found that only the 6D substitution line was significantly more resistant to take-all (Gaeumannomyces graminis var. tritici) than 'Winalta'. Substitutions in 'Winalta' for chromosomes 5D and 6D by homeologous chromosomes from Agropyron elongatum and chromosome 4B for chromosome 4 from Agropyron intermedium had no effect on resistance to take-all. The wheat – Agropyron trichophorum amphiploid 'Agrotana' was also found to be susceptible to take-all. Vernalization increased take-all severity and obscured differences between 'Winalta' – Ae. squarrosa 6D and susceptible lines and cultivars. 'Winalta' – Ae. squarrosa 6D had significantly less disease and a higher plant weight than 'Winalta' at low and moderate inoculum concentrations, but the resistance of 'Winalta' – Ae. squarrosa 6D was not effective at the highest inoculum concentration. There was a strong negative correlation between take-all severity and plant weight.Key words: Gaeumannomyces graminis var. tritici, Aegilops squarrosa, Agropyron elongatum, Agropyron intermedium, Triticum aestivum, chromosome substitution, resistance.