Potential of hydroxamic acids in breeding for aphid resistance in wheat

Abstract

Swedish wheats were analysed at the seedling stage for hydroxamic acids (Hx), a family of natural aphid resistance factors. Analysis comprised the historical development from old landraces to modem cultivars, and included cultivars in the Swedish National List of Cultivars for 1992-93. Spring and winter wheats contained similar average Hx concentrations, 2.12 +/- 0.801 (n = 26) and 2.37 +/- 0.816 (n = 49) mmol/kg fr. wt, respectively. Cultivars recommended for 1992-93 showed lower levels of Hx, 1.14 +/-0.574 (n = 7) and 1.97 +/- 0.751 (n = 8), respectively. Breeding wheat for higher Hx levels as a means of obtaining increased aphid resistance is discussed.