Intergeneric hybrids between Hordeum jubatum (4x) and triticale (x Triticosecale Wittmack)

Hybrids of Hordeum jubatum (4x) were produced with two isogenic lines of 6x triticale (x Triticosecale Wittmack) cv. DRIRA, one carrying the normal heterochromatic block on the long arm of 7R (cv. DRIRA HH) and the other lacking 90% of it (cv. DRIRA EE). The two hybrids were produced at relative frequencies of 1.1 and 0.9% of pollinated florets, respectively. The chromosome pairing in both of these hybrids was negligible (chiasmata frequencies 0.11 and 0.15), indicating that heterochromatin on 7R had no effect on chromosome pairing in H. jubatum and that the expected autosyndetic pairing between two related genomes of H. jubatum was absent in this combination