Formation of a synthetic karyotype of tetraploid triticale

Abstract

Thirteen forms of 4x triticale were analyzed using a C-banding technique. All forms contained 14 R-genome chromosomes and 69 different combinations of A-, B-, and D-genome chromosomes from wheat were identified. The following general features of the formation of the synthetic karyotype of 4x triticale were found: there was a different rate at which homoelogous groups were stabilized; there was a selection against "hétérozygotes" (AB); and there was an effect exerted by the chromosomal constitution of some homoeologous groups on the rate and direction of stabilization in other groups. The two most probable variants of the wheat genome in 4x triticale are 1B, 2B, 3A, 4A, 5A, 6A, 7B and the reverse. The selection occurred at the level of homoeologues, and the selective advantages are determined by genotype-environment interactions. The environmental factors included both natural and artificial selection pressures. The data presented here can be used for the creation of a hypothesis concerning the practical approaches in chromosomal engineering of cereals.Key words: 4x triticale, general features of karyotype formation, C-banding.