Figure 1

Chromosomal evolution network. Relationships of the 6 cytotypes of M. americana analyzed and their geographical distribution, modified from Abril et al. [12]. The ancestral karyotype originated the Linage A) (northwest of Brazil) and Linage B) (south and north of Brazil). The chromosomal differentiation of each cytotype from the common ancestor (2n=52-53; FN = 54) was achieved by the fixation of different rearrangements: Linage A is constitute by Ju: Juína (2n=44/45; FN=48) a centric-fusion translocation (red bar) and three tandem-fusion translocations (green bar), and Ro: Rondônia (2n=42/43; FN=46) a rearrangement of the Juína cytotype with another tandem-fusion translocation (green bar). The Linage B is constitute by Pr: Paraná (2n=52/53; FN=56) a pericentric inversion (blue bar) from the ancestral karyotype; Ca: Carajás (2n=50/51; FN=54) a rearrangement of the Paraná cytotype with another tandem-fusion translocation (green bar); Sa: Santarém (2n=50/51; FN=56) a rearrangement of the Paraná cytotype with another centric-fusion translocation (red bar); and Ja: Jarí (2n=48/49; FN=56) a rearrangement of the Santarém cytotype with another centric-fusion translocation (red bar). 2n = diploid number / FN = fundamental number. The colors bars indicate the chromosome rearrangements accumulated by the cytotype.