Reorganization of wheat and rye genomes in octoploid triticale (× Triticosecale)

Abstract

Main conclusion The analysis of early generations of triticale showed numerous rearrangements of the genome. Complexed transformation included loss of chromosomes, t-heterochromatin content changes and the emergence of retrotransposons in new locations.This study investigated certain aspects of genomic transformations in the early generations (F5 and F8) of the primary octoploid triticale derived from the cross of hexaploid wheat with the diploid rye. Most of the plants tested were hypoploid; among eliminated chromosomes were rye chromosomes 4R and 5R and variable number of wheat chromosomes. Wheat chromosomes were eliminated to a higher extent. The lower content of telomeric heterochromatin was also found in rye chromosomes in comparison with parental rye. Studying the location of selected retrotransposons from Ty1-copia and Ty3-gypsy families using fluorescence in situ hybridization revealed additional locations of these retrotransposons that were not present in chromosomes of parental species. ISSR, IRAP and REMAP analyses showed significant changes at the level of specific DNA nucleotide sequences. In most cases, the disappearance of certain types of bands was observed, less frequently new types of bands appeared, not present in parental species. This demonstrates the scale of genome rearrangement and, above all, the elimination of wheat and rye sequences, largely due to the reduction of chromosome number. With regard to the proportion of wheat to rye genome, the rye genome was more affected by the changes, thus this study was focused more on the rye genome. Observations suggest that genome reorganization is not finished in the F5 generation but is still ongoing in the F8 generation.

Assessing How the Aluminum-Resistance Traits in Wheat and Rye Transfer to Hexaploid and Octoploid Triticale

“…The important observation from both sets of lines was that the Al resistance of rye was incompletely transferred to triticale—whether to a hexaploid or a octoploid triticale. Similar observations have been made previously for other rye genes in triticale (Neves et al, 1995 ; Kalinka and Achrem, 2018 ). By contrast, the Al resistance traits from hexaploid wheat did transfer more successfully to octoploid triticale.…”

“…Furthermore, homeolog copies of all genes in allopolyploids are not expressed equally. Sequences can be lost and mutations generated due to chromosomal rearrangements or transposon activity (Ma and Gustafson, 2008 ), and gene transcription can be affected by epigenetic modifications and microRNAs (Cheng and Murata, 2002 ; Kashkush et al, 2002 , 2003 ; Kraitshstein et al, 2010 ; Li et al, 2014 , 2015 ; Kalinka and Achrem, 2018 ). Cytosine residues in DNA are prone to methylation when they occur as CpG, CpHpG, and CpHpH sites (where H represents any nucleotide except guanine) and methylation of gene promoter regions can interfere with transcription.…”

“…More than one ALMT and MATE gene could contribute to anion efflux (see Introduction). The variation may also be related to the instability of the primary triticale lines which can continue in subsequent generations (Ma and Gustafson, 2008 ; Kalinka and Achrem, 2018 ). The grain used in these experiments were bulked on two occasions so some variation was not unexpected.…”

Molecular diversity analysis of genotypes from four Aegilops species based on retrotransposon–microsatellite amplified polymorphism (REMAP) markers

“…REMAP markers were also used to analyze genetic similarity in triticale. The obtained level of polymorphic bands was 88.46% (Kalinka and Achrem 2018).…”

THE USE OF Vrn GENES FOR CREATION OF TRITICALE FORMS WITH DIFFERENT LENGTH OF VEGETATION PERIOD (review)

“…Эти ПРА характеризуются цитологической нестабильностью и высокой частотой анеуплоидов. На протяжении ряда поколений у них происходит утрата хромосом до формирования ста- Работа была поддержана бюджетным проектом ИЦиГ СО РАН, бюджетный проект ¹ 0324-2015-0005. бильного гексаплоидного уровня (1,2). Из-за пониженной озерненности колоса сорта октаплоидных (½8) тритикале в сельскохозяйственном производстве не используются.…”