Dynamics of the Centromeric Histone CENH3 Structure in Rye-Wheat Amphidiploids (Secalotriticum).

The centromeres perform integral control of the cell division process and proper distribution of chromosomes into daughter cells. The correct course of this process is often disrupted in case of remote hybridization, which is a stress factor. The combination of parental genomes of different species in a hybrid cell leads to a "genomic shock" followed by loss of genes, changes in gene expression, deletions, inversions, and translocations of chromosome regions.

CHARACTERIZATION OF CENTROMERIC HISTONE H3 VARIANTS IN ALLOPOLYPLOIDS OF WHEAT AND RYE.

Chromosome elimination of one parental species in hybrid cell observed even after successful fertilization is one of a common phenomenon and the main problems of remote hybridization. Centromeres regulate the process of faithful segregation of chromosomes during cell division. Constant component of the centromeric chromatin is a specialized histone H3 modification (CENH3).

[Cytogenetic genome stabilization in secalotriticum (x Triticosecale derzhavinii secalotriticum rozenst., et Mittelst., s/RRAABB, 2n = 42)].

The article presents the results of cytogenetic research of the genome stabilization in hexaploid secalotriticum F(1-9) (s/RRAABB, 2n = 6x = 42). Nucleo-cytoplasmic specificity and cytogenetic factors of genome stabilization were established in secalotriticum: subspecies specificity of cytotype, genotype specificity of hybrids, origin, polar centromere orientation, division and segregation type of the chromosomes in meiosis. The necessity for developing independent trends in heteroplasmic triticales breeding was substantiated.

[Analysis of meiotic genome stabilization in the rye-wheat amphidiploid secalotriticum (×Secalotriticum, s/RRAABB, 2n = 42)].

The results of cytogenetic studies of genome stabilization in secalotriticum are presented. Comparative analysis of microsporogenesis in hexaploid secalotriticum, triticale, and reciprocal hybrids of them (S/RRAABB, T/AABBRR, 2n = 6x = 42) was carried out. The cytogenetic properties and genotypic factors of genome stabilization in heteroplasmic triticale were found.