botanyone
Genome restructuring is an ongoing process in natural plant populations and the influence of environmental changes on the genome is crucial, especially during periods of extreme climatic fluctuations. Belyayev and Raskina review long-term data on the cytogenetic characteristics of diploid Aegilops speltoides populations and find that marginal populations are distinguished by numerical chromosomal aberrations, spontaneous aneuploidy, B-chromosomes, repatterning of rDNA clusters, and reduction in species-specific and tribe-specific tandem repeats. It is likely that a specific combination of gene mutations and chromosomal repatterning has produced the evolutionary trend in each specific case. The appearance of a new chromosomal pattern is considered an important factor in promoting the emergence of interbreeding barriers.
