Abstract
Thirty doubled haploid lines of wheat derived from an F1 hybrid carrying the gibberellininsensitive semi-dwarfing genes Rht1 and Rht2 were used to assess their effects on agronomic traits. The effect of these genes was additive for the reduction of plant height. Semidwarf lines carrying either Rht1 or Rht2 produced the same grain yield as tall lines did under artificial support to prevent lodging. Dwarf lines carrying both genes showed a remarkable decrease in grain yield. The genotype background in hybrid recombination modified both plant height and grain yield, but did not produce a variation that exceeded the effects of semi-dwarfing genes.
