Genomic dominance as a force shaping evolution of plant wide hybrids

01/2020 - 12/2022
Project number
Principle investigator
Interspecific hybridization is one of key processes underlying plant speciation. Parental
genomes usually do not intermingle in hybrid nuclei but in some hybrids pairing of
homoeologous chromosomes does take place during meiosis. This opens a possibility for the
reshuffling of their genomes. Such homoeologous pairing is frequent in Lolium × Festuca
hybrids, creating truly hybrid genomes. However, in subsequent generations chromatin of
Festuca is gradually replaced by that of Lolium. The mechanisms underlying this genome
dominance of one parental genome over the other are unknown and this is the issue we
propose to study. We will conduct a study on the occurrence, mechanisms and significance of
genome dominance for the stability of hybrid genomes. We will use hybrids of Lolium × Festuca
and Allium cepa × A. roylei, both of which display frequent homoeologous pairing of
chromosomes, gradual elimination of one of the parental genomes over generations, and
represent independent monocot lineages. We will also study nucleolar dominance as another
aspect of genome dominance.