Figure 3. Triplicate state of Vitis chromosomes.

The formation of triplets is based on the homology among groups of genes located on specific chromosome fragments and homologous DNA segments present on other chromosomes [5], [6], [22]. Assignment of chromosomes to either Va (green) or Vc (red) genomes was based on cluster i) similarity and ii) identity scores. Grey lines represent chromosomes not assigned to the two genomes; they could represent a third genome (Vb), for which we lack direct proof. Roman numbers indicate chromosomes, while Arabic numbers represent the length of the chromosomes in megabase pairs. Exceptions to the assignment of chromosomes are represented by chromosome IV and XIV, which could not be definitively assigned to one of the putative genomes.