Chromosome morphology of certain races of maize in Latin America

The study of the morphological features of the mid-prophase chromosomes of the microspore-mother-cells of maize was initiated thirtyfive years ago, when it was found that aceto-carmine stained the chromosomes at this early phase. As time passed, more and more data were published on the chromosome knob complement, the most variable feature of the mid-prophase chromosomes of maize. These data came from material found in the Americas ranging from the Northern United States in North America to Chile in South America. During the years 1960 to 1962, the authors studied the chromosomes of some of the primitive races of maize in Mexico, Central and South America, and of races and varietal groups of Central America and the Caribbean Islands. These studies were planned to determine the morphological features of the chromosomes of distinct types of maize, hoping to detect characteristics associated with each race and with races from different areas and environments.