Relationships among Kernel Weight, Early Vigor, and Growth in Maize

Abstract

Lack of early season vigor in maize ( Zea mays L.) hybrids and inbreds from the USA limits their use in places with cool humid springs. Kernel size may be related to early growth of maize. Our objectives were to estimate general combining ability (GCA), specific combining ability (SCA), and reciprocal effects (RE) for early vigor and plant growth‐related traits and to determine the relationship between these effects and those of kernel weight. Ten maize inbreds were crossed in diallel fashion, including reciprocals in two different plots. Kernel weight was recorded for each seed source for each hybrid. The 90 hybrids were evaluated for 2 yr in a split‐plot design where genotypes were the main plots and seed sources were the subplots. Traits were early vigor, plant weight, pollen and silk date, leaves below the ear, total leaf number, and plant height. Significant GCA was detected for all traits except plant weight, and SCA was significant for all traits except kernel weight. Significant RE was detected for kernel weight, early vigor, and pollen and silk date. Inbred EP42 had the highest GCA and a favorable RE for early vigor. Regression on the RE of kernel weight was significant for the RE of early vigor ( R 2 = 0.67), plant weight { R 2 = 0.36), and pollen ( R 2 = 0.52) and silk date ( R 2 = 0.45). The inbreds producing heavier kernels should be used as seed producing parents to obtain hybrids with better early vigor and earlier flowering dates.