Selection for Seed Setting in Hybrid Populations of Autotetraploid Barley, Hordeum vulgareL. emend Lam.1

Selection for increased seed set was carried out in the segregating generations of four hybrid populations derived from intercrosses of five autotetraploid lines. The seed set of the early generations of the hybrid populations was higher than the respective parents and was maintained through the F5to F10generations. Selection, however, was ineffective in increasing the percentage seed set. The greater seed set of the hybrids was probably not due to heterosis unless a great deal of preferential pairing occurred. Selection was also carried out for reduced seed set and this was also ineffective. The lack of success in selection indicates a need to select on the basis of specific combining ability to improve the seed set of autotetraploid barleys.