Nuclear DNA content variation in the ancient indigenous races of Mexican maize

From eight maize accessions representing the four ancient indigenous races of mexican maize the nuclear DNA content was determined by flow cytometry. No significant difference between accessions of the same race was observed. Significant differences were found among the races, with two clusters observed. The lowland races had an average genome size of 12·6 pg while the highland races showed an average genome size of 11·1 pg. A significant negative correlation between genome size and altitude was observed.