Cytogenetic studies of progeny from the intergeneric crosses Elymus × Hordeun and Elymus × Secale

Meiotic pairing was studied in three Elymus species, E. pseudonutans (2n = 28), E. shandongensis (2n = 28), and E. semicostatus (2n = 28), as well as their dihaploids (2n = 14) which were produced from the intergeneric crosses E. pseudonutants × Hordeum vulgare ssp. spontaneum, E. shandongensis × Triticum aestivum, and E. semicostatus × H. bulbosum. An average of 12.82 I + 0.55 II + 0.03 III; 12.59 I + 0.65 II + 0.01 III, and 12.70 I + 0.76 II + 0.02 III per cell characterized meioses in the dihaploids, respectively. Intergeneric hybrids (2n = 21) of the three species were also obtained with diploid Secale cereal and S. montanum. Meiotic configurations of the hybrids were 14.64 I + 2.82 II + 0.20 III + 0.01 IV and 16.38 I + 2.02 II + 0.16 III for two combinations of E. pseudonutans × S. cereale; 15.59 I + 2.62 II + 0.08 III and 19.63 I + 0.65 II for E. shandongensis × S. cereale and E. semicostatus × S. montanum, respectively. A large number of chromosomes were involved in secondary associations in the different combinations. The study revealed (i) low affinity between S and Y genomes in the investigated Elymus species, (ii) a certain degree of homoeology between genomes of Elymus (S or Y) and rye (R), and (iii) that the rye genome affects homoeologous chromosome pairing between different genomes in the Elymus species.