LACK OF RELATIONSHIP BETWEEN RELATIVE MATURITY AND GENOME SIZE IN HYBRID MAIZE

Correlations between genome size and area of geographic adaptation have been reported in maize (Zea mays L.). Such correlations have been suggested to occur due to lower genome sizes being more favorable where shorter growing seasons exist. The objective of this study was to determine if genome size and relative maturity are correlated in hybrid maize. Thirty hybrids, obtained from Pioneer Hi-Bred International, Inc. (Johnson, IA), were analyzed. Genome size determinations were made using flow cytometric techniques. No correlation between genome size and relative maturity was observed. Since the area of adaptation of these hybrids encompasses a wide range of latitudes, there appears to be no correlation between genome size and latitude as well. The lack of correlations among these characters may result from the breeding structure of hybrid maize.