Meiotic behavior and chromosomal irregularities in two <i>Tradescantia</i> L. species

Tradescantia spathacea (2n=2x=12) and T. pallida (2n=4x=24), two species of Tradescantia L., were the subjects of a comprehensive meiotic investigation. The genus appears highly interesting as a tool for studying complex chromosomal rearrangements. During meiosis, both species showed diverse multivalent arrangements with two distinct orientations—adjacent and alternating. Some meiotic anomalies, including chromosome stickiness, unequal distribution during anaphase, lagging chromosomes, chromosomal fragments, and chromosomal bridges, were observed as a result of adjacent orientation, inappropriate spindle apparatus functioning, and paracentric inversions. Despite these irregularities, over 95% of pollen fertility was recorded in both species. This is most likely due to the evolution of permanent translocation heterozygosity (PTH) in Tradescantia. Our study contributes to the knowledge of intricate chromosomal arrangements in the genus Tradescantia for further cytogenetic research.