Using carrot centromeric repeats to study karyotype relationships in the genus Daucus (Apiaceae)

Area of Science:

• Plant genetics
• Molecular cytogenetics
• Evolutionary biology

Background:

• Karyotypes evolve, leading to variations even in related taxa.
• The genus Daucus, including the cultivated carrot, is a diverse model for studying karyotype evolution.
• Previous studies lacked detailed karyomorphological analysis for many Daucus species.

Purpose of the Study:

• To investigate karyotype relationships within the genus Daucus.
• To explore the chromosomal distribution of carrot centromeric repeats (CentDc).
• To perform detailed karyomorphological analysis in Daucus accessions.

Main Methods:

• Fluorescence in situ hybridization (FISH) to map CentDc repeats.
• Analysis of 34 Daucus accessions and related species.
• Detailed karyomorphological measurements in 16 accessions.

Main Results:

• CentDc repeats were found in centromeric regions of all chromosomes in 20 accessions (11 taxa).
• Centromeric localization of CentDc was conserved, though the number of positive chromosome pairs varied.
• Karyomorphological analysis revealed inter- and intraspecific relationships.

Conclusions:

• The presence of CentDc in both Daucus subclades and an outgroup suggests its ancestral nature.
• Findings support further evolutionary, cytotaxonomic, and phylogenetic studies in Daucus.
• The study enhances understanding of centromeric satellite evolution in plants.