AGRONOMIC AND QUALITY CHARACTERS OF NEAR-ISOGENIC LINES OF WHEAT CARRYING GENES FOR STEM RUST RESISTANCE

Two sets of near-isogenic lines of wheat carrying single genes for ste m rust resistance were grown in yield tests to determine whether the r esistance genes were deleterious. One set was based on the cultivar Ma rquis and the second set on a susceptible, day-length insensitive line , LMPG. The results indicated that the effects of resistance genes var y with different genes and different environments. However, there appe ared to be a tendency for resistance genes to reduce yield. In most ca ses the reductions were too small to be of much concern to wheat breed ers.