| Information on the crossability of tetraploid rye with
T. vulgare and Triticale S. BOROJEVIC and K. BOROJEVIC Faculty of Agriculture, Novi Sad, Yugoslavia In the program of species hybridization in Triticinae, crosses between tetraploid rye with T. vulgare and Triticale have been included. It was believed that the crosses between vulgare wheat and tetraploid rye could show better crossability than between vulgare wheat and diploid rye and possibly furnish better material than present Triticale strains which are rather poor under our condition. Different varieties of vulgare wheat were crossed with tetraploid rye (Steel rye and Petkuser). Direct and reciprocal crosses were made for two years. All these crosses, however, were completely unsuccessful, giving no seeds. As for the crosses between Triticale and tetraploid rye, one combination (Triticale A x Petkuser) where extensive crosses were made, gave viable seeds. The F1 plants were very vigorous having beautiful long heads, intermediate in appearance. Since the doubling of the chromosomes was not undertaken, the F1 plants were completely sterile. Meiosis showed good pairing of seven rye chromosomes and the rest were as univalents showing the tendency of almost equal distribution (in numbers) to the poles. Next year many new crosses between Triticale and tetraploid rye were made with the purpose to apply colchicine treatment. Unfortunately the crosses did not succeed, probably due to some mistakes made in time or other circumstances during the crossing period. Obtained informations support Muntzing's assumption that the ratio of wheat to rye genomes seems to be important for the fertility of the Triticale types. |