A New Source of Resistance to Puccinia striiformis f. sp. tritici in Spring Wheats (Triticum aestivum)

Abstract
The use of P. striiformis f. sp. tritici pathotypes virulent or avirulent with respect to both Yr6 and a previously undescribed source of resistance, designated YrA, allowed the recognition of the corresponding host resistance genes m a range of Australian and exotic spring wheats. The phenotypes conferred by the YrA resistance varied when exposed to contrasting light intensities in the post‐inoculation phase. The implications of the results in international studies of host resistance to P. striiformis f. sp. tritici are discussed.