Study of ribotypes of experimentally obtained hybrids of polyploid species of the genus Avena L.

Abstract

For the first time, using next generation sequencing (NGS) on the Illumina platform of the ITS1 sequence and the beginning of the 5.8S rRNA gene, the current state of genomic compositions of complex cultivated oat hybrids based on the Avena macrostachya was studied. It was shown that A. sativa х A. macrostachya hybrid used for further hybridization with other oat species actually acts as a “pure” A. sativa in the next generations of hybridization. The most represented ribotypes (abundant by the number of marker sequences reads) are inherited from the hexaploid A. sativa (ACD genome). Other parental taxa, such as hexaploids A. byzantina, A. sterilis (ACD-genome), tetraploids A. magna, A. murphyi (AC-genome), as a rule, form the second most abundant ribotype in hybrids. Also, this ribotype includes the minor components of A. sativa rDNA (probably left over from common ancestors). We assume that this is due to the harsh consequences of the reorganization of genomes in interspecific hybrids from crossing cultivated oat with wild ones, as a result of which the number of sequences of these species in the genomic set of hybrids naturally gradually decreases. It especially manifests in the artificial hybridization of hexaploids of the A. sativa group (A. sativa and A. fatua, ACD-genome) and A. macrostachya (homotetraploid CmCm). In such hybrids, according to our data, the loss of entire chromosomes of A. macrostachya sometimes occurs, due to which we do not see rDNA sequences of this species at all.