Construction of secalotriticum (Rye-wheat amphidiploids with the rye cytoplasm (RRAABB, 2n = 42)), the formation of the karyotypes of the F1BC1 and F1BC2 rye-triticale amphidiploids, and commercial and biological characteristics of the early secalotriticum generations

Abstract

The karyotype formation was studied in the F1BC1 and F1BC2 hybrids of Secale cereale L. ssp. tetraplodium Kobyl. (RRRR, 4x = 28) and Triticale (AABBRR, 6x = 42). The hybrid karyotypes were heterogenomic for homeologous chromosome groups of the wheat and rye genomes. The hybrids differed in cytological stability, the balance of chromosomes of the original species, and the fertility of spikes. The majority of F1BC1 and F1BC2 plants were cytologically unstable and unbalanced in chromosome composition and displayed a low spike fertility. Cytologically stable hexaploids occurred in F1BC1 and F1BC2 at a frequency of 1.0 and 9.5%, respectively. The resulting hexaploid secalotriticum lines (RRAABB, 6x = 42) were genotypically diverse and morphogenetically various. The genetic factors responsible for the diversity of the F1BC1 and F1BC2 rye-triticale amphiploids and early secalotriticum generations are discussed.