Fig. 5
From: Cytoplasmic genome contributions to domestication and improvement of modern maize
A model for the origin of NA, CMS, and NB cytotypes in maize mitogenomes. A Nucleotide diversity (π, y-axis) of mitogenome (x-axis) in the region of 177–206 kb among improved lines, landraces, and Z. parviglumis. An asterisk indicates the change between landraces or improved lines and wild maize with statistical significance (P < 0.05, two-tailed Student’s t-test). B Mitogenome of maize was derived from Z. parviglumis. Interaction of the Z. parviglumis cytoplasm with the nuclear genomes through modern breeding programs produced mitogenome cytotypes including NA and CMS (S, T, and C). Approximately ~ 5000 years ago, NB cytotype of the mitogenome was generated possibly through recombination of NA and CMS (S, T, and C) cytotypes. The combination of NA and CMS cytotypes has been retained through artificial selection, while the NB cytotype became predominant in the commercial inbreed lines associated with maize improvement