Behavior of Intergeneric Hybrids between Hordeum vulgare L. (4x) and an Elymus mollis Type

Abstract

Partially fertile F₁ plants were obtained from crosses between synthetic autotetraploid Hordeum vulgare L. (2n=28) and a tetraploid Elymus mollis L. type (2n=28). The F₁ plants were about the same size as the barley parent. Spikelets were sometimes altered in arrangement on the rachis, but in general more closely resembled the barley parent than Elymus. The seeds on the selfed F₁ spikes were larger and more shriveled than those of autotetraploid barley.
Elymus and Hordeum chromosomes could not be distinguished in most of the meiotic cells examined in the tetraploid and triploid hybrids. However, chromosomes of the Elymus parent appeared to be slightly smaller than chromosomes of the barley parent. At least eight of the 14 Hordeum chromosomes paired with eight from Elymus in the tetraploid hybrid (2n=28) and both auto and allo-syndetic pairing were observed. Cytological examinations of microsporocytes from triploid plants (2n=21) obtained from crosses of the tetraploid hybrid (2n=28)×H. vulgare L. (2n=14) showed similar types of chromosome pairing as observed in the tetraploid hybrid.