genus onobrychis is an important forage crop consisting of approximately 130 annual and perennial species. the present research focused on the cytological studies of embryogenic (e) and non-embryogenic (ne) callus as well as root meristem cells of in vitro and in vivo grown plants. on the contrary to the previous studies, a diploid viciifolia variety with 2n= 2x= 16 chromosomes was observed for...

INTRODUCTION Polyploidy is an intriguing phenomenon in plants that has provided an important pathway for evolution and speciation. Although the first polyploid was discovered over a century ago, the genetic and evolutionary implications of polyploidy are still being elucidated (Bennett, 2004; Soltis et al., 2003). On a more practical level, there are many opportunities for utilizing polyploidy ...

Polyploidy is an evolutionary process whereby two or more genomes are brought together into the same nucleus, usually by hybridization followed by chromosome doubling. As a result, the new polyploid is genetically isolated from its diploid progenitor(s) and a new species is formed. The importance of polyploidy was recognized early in the 20th century and for the past decades many studies have a...

Polyploidy is an evolutionary process whereby two or more genomes are brought together into the same nucleus, usually by hybridization followed by chromosome doubling. As a result, the new polyploid is genetically isolated from its diploid progenitor(s) and a new species is formed. The importance of polyploidy was recognized early in the 20th century and for the past decades many studies have a...

BACKGROUND Several lines of evidence indicate that polyploidy occurred by around 54 million years ago, early in the history of legume evolution, but it has not been known whether this event was confined to the papilionoid subfamily (Papilionoideae; e.g. beans, medics, lupins) or occurred earlier. Determining the timing of the polyploidy event is important for understanding whether polyploidy mi...

Polyploidy has been reported in several animal cells, as well as within humans; however the mechanism of developmental regulation of this process remains poorly understood. Polyploidy occurs in normal biologic processes as well as in pathologic states. Decidual polyploid cells are terminally differentiated cells with a critical role in continued uterine development during embryo implantation an...

Polyploidy is a common mode of evolution in flowering plants. The profound effects of polyploidy on gene expression appear to be caused more by hybridity than by genome doubling. Epigenetic mechanisms underlying genome-wide changes in expression are as yet poorly understood; only methylation has received much study, and its importance varies among polyploids. Genetic diploidization begins with ...

The discovery of ancient whole-genome duplications in eukaryotic lineages has renewed the interest in polyploidy and its effects on the diversification of organisms. Polyploidy has large-scale effects on both genotype and phenotype and has been linked to the evolution of genome size, dioecy, and changes in ecological interactions, such as pollinator visitation. Here, we take a molecular systema...

chromosome counting was performed in nine populations of achillea tenuifolia lam and eight populations of a. bieberestinii afan (asteraceae) collected from hamedan and kermanshah provinces in the west of iran. chromosome numbers in both species varied from 2n=2x=18 to 2n=4x=36. some populations of both species showed (2n=4x=36) chromosome number that is the first report as polyploidy levels. an...