SECALOTRITICUM 4X - PRODUCTION, CHROMOSOME CONSTITUTIONS AND FERTILITY

Rye cytoplasmic tetraploid triticale was obtained from the backcross hybrids (rye 4x x triticale 4x with wheat cytoplasm) x triticale 4x. In BC1 - F2 generation 29 plants were obtained with 8 stabilized and 2 unstabilized chromosomes constitutions. The most numerous group represented plants with chromosomes constitution 1A, 2A, 3B, 4A, 5B, 6A, 7B. In the next generations, as the result of selection of plant fertility, chromosomes segregation in the wheat genome was observed - new chromosomes constitutions were established and simultaneously the already existing were eliminated. In F3 - F7 generations 11 stabilized new chromosomes constitutions and 20 unstabilized segregated. From the F3 generation there appear the majority of plants, by which in the first homoeological group chromosome 1B exists, in the fifth-chromosome 5B, while chromosome 2B was entirely eliminated. Fertility selection showed the appearance of two most numerous groups of plants with karyotypes 1B, 2A, 3B, 4A, 5B, 6A, 7B and 1B, 2A, 3B, 4B, 5B, 6A, 7B. Plants of F2 - F5 progeny, showed pronounced tendency to free pollination and from the F6 generation plants showed increased selffertility. The highest fertility, in the whole experiment cycle, showed the plant from F3 generation,setting 62.33 seeds/ear, in spite of having unstabilized fourth homeological group. In the last generation investigated, the highest fertility amounted 49 seeds/ear.