Chromosome C-banding of Zea mays and its closest relatives

Abstract

An established C-banding technique was modified to consistently yield complete sets of distinct, sharply banded chromosomes in Zea. It was used to demonstrate similarities and differences among heterochromatin patterns of different Zea taxa. The C-banding patterns showed a general agreement with heterochromatic knob positions known from pachytene studies. Two groups of banding patterns could be distinguished. Those taxa with bands that were almost exclusively terminally positioned included Z. mays ssp. parviglumis var. huehuetenangensis, Z. diploperennis, Z. perennis, and Z. luxurians. In the last mentioned, previously unknown heterochromatic regions were found. Both terminal and subterminal band positions were found in Z. mays, Z. mays ssp. mexicana, and Z. mays ssp. parviglumis var. parviglumis. On the basis of these results, and those of other workers, the taxonomic treatments of Z. mays ssp. parviglumis var. huehuetenangensis, and of Z. diploperennis and its autotetraploid derivative Z. perennis are questioned.