Development and Characterization of Wheat-Rye Hybrids Produced by Meiotic Restitution

The nature of the formation of fertile progenies of F2 and F3 generations of wheat–rye hybrids obtained as a result of meiotic restitution using the Saratovskaya 29 variety (C29 x R) and the wheat–rye substituted line 1Rv(1A) (1Rv (1A) × R) was studied. The karyotype analysis of the F₂Triticum aestivum L. cv. Saratovskaya 29 × Secale cereale L. var. Onochoyskaya (S29 × R) hybrid using C-banding revealed 56 chromosomes; among them were 42 wheat chromosomes and 14 rye chromosomes. The karyotype of the F₂ 1Rv(1A) × R hybrid contained 46 chromosomes, of which three pairs of rye chromosomes 1R1R4R4R2RL2RL, 1R1R replaced the chromosomes 1A1A, and 2RL2RL and 4R4R were additional to the wheat chromosomes. In the F₃ generation of S29 × R hybrids, the octoploid number of chromosomes with aneuploidy of single rye and wheat chromosomes was preserved, while in the 1Rv(1A) × R hybrids the number of chromosomes varied from 42 to 49, but in most plants 2n = 46 was retained. Meiosis of the F₃ 1Rv(1A) × R hybrids was more stable than that of the S29 × R hybrids. The average number of univalents in 1Rv(1A) × R hybrids was 1.54 ± 0.17, which was significantly lower than in S29 × R hybrid progenies (2.56 ± 0.23 and 2.07 ± 0.27). The F₃ С29 × R and 1Rv(1A) × R hybrids were characterized by the variability in the seed set and 1000-grain weight. On average, С29 × R plants produced a smaller number of grains with but larger size than 1Rv(1A) × R plants, forming more grains with lower 1000-grain weight. The obtained results indicate the influence of the substitution 1Rv(1A) on the reorganization of hybrid genomes.