THE INHERITANCE OF RUST RESISTANCE: VII. THE INHERITANCE OF RESISTANCE TO RACES 15B AND 56 OF STEM RUST IN ELEVEN COMMON WHEAT VARIETIES OF DIVERSE ORIGIN

Abstract

In an attempt to locate new genes for stem rust resistance, 11 varieties of wheat of as diverse origins as possible were studied. Each variety was backcrossed to the susceptible parent Marquis. The F2 families from the backcrosses were tested with races 15B and 56, and the inheritance of resistance determined. The genes carried by each variety were identified from the results of test crosses with varieties carrying known genes and with lines of Marquis carrying single genes for resistance. Most of the resistance present in the 11 varieties could be accounted for on the basis of known genes (Sr6 – Sr10). However, at least one new gene conditioning moderate resistance to race 15B, and possibly one or more new genes conditioning moderate resistance to race 56, were identified.