Improving Kernel Weight and Number in Some Maize Subspecies Crosses

Four maize subspecies inbreds were crossed to each other in the fall planting season in 2018. This was on the x- farm of the college of Agric. Engineering Sciences /University of Baghdad. F1 ear seeds were harvested, dried and shelled. The maize subspecies inbreds were Zea mays L., saccharata (S), Zea mays L. indentata, D and J, and Zea mays L., indurata (P) of popcorn. In fall season of 2019, the F1 crosses seeds were grown on the same farm for comparison. Data were recorded on all crosses plants and their four inbreds. The objective of this trial was to determine the inheritance of kernel colour, kernel weight, kernel shape and their relationships with plant grain yield. The results showed that plant height of crosses was not coincided with plant leaf area. Number of ear kernels and kernel weight were the direct components of grain yield. Number of ear kernels was a result of number of kernels per row and number of ear rows. Two crosses gave significantly higher grain yields. They were D×S, and J×D, which gave 13.3 t/ ha and 11.9 t/ha, respectively. The genetic diversity of D line was thought to be due to its late flowering. Shape of kernel was thought to be controlled by many genes, and so, kernel colour. Kernel dent was thought to be dominant or incomplete dominant. It was concluded that hybrid vigour is controlled by many plant attributes, such as SNP, transposons, methylation, epigenome, and parental imprinting of crossed inbreds. We recommend identification of some diverged phenotypic plant traits of crossed inbreds to have elite hybrids.