Variability of Indicators and Processes in a Long Structured Phylogenetical Branch of Angiosperms. Part 2. Berberidaceae and Ranunculaceae Chain Links

Resumo

The evolutionary process proceeding in the genomes of Berberidaceae and Ranunculaceae, two families of dicotyledonous angiosperms, was analyzed. Regular variation of the basic chromosome numbers and GC content of the ITS1-5.8S-ITS2-site of rDNA, as well as the chromosome number in the Berberidaceae family (13 → 10 → 8 → 7 → 6), were observed. It is possible that x = 6 can change independently of x = 10 changes. In the Ranunculaceae family, the sequence was 13 → 10 → 9 → 7 → 8. The GC content in rDNA in both families decreased from 71–75 to 46–52% in spacers and from 56 to less than 53% in the sequences encoding 5.8S rRNA. In Ranunculaceae, there is a secondary increase in the GC content in rDNA, followed by a further decrease in this parameter.