HYBRIDIZATION OF TRITICUM AND AGROPYRON: I. CROSSING RESULTS AND DESCRIPTION OF THE FIRST GENERATION HYBRIDS

Abstract

Two species of tetraploid (2n = 28) and three varieties of hexaploid (2n = 42) wheat were crossed with A. glaucum (2n = 42), and A. elongatum (2n = 70), with an average crossing success of 18%. The seed obtained from tetraploid wheat × A. glaucum was slightly plumper and germinated better than that obtained from tetraploid wheat × A. elongatum. On the other hand, hexaploid wheat × A. elongatum gave decidedly plumper and better germinating seed than hexaploid × A. glaucum.Grown under greenhouse conditions the F₁ hybrids proved to be self-sterile and perennial in habit, with hybrid vigor strongly marked. The hybrids were, in general, intermediate in morphological characters, but with somewhat more resemblance to Agropyron than to wheat. This dominance, whole or partial, was more noticeable in the A. elongatum than in the A. glaucum crosses. Dominance phenomena are discussed in relation to current theories.