The researchers studied how different maize plants combine to create new hybrids with improved traits. They crossed 7 diverse inbred maize lines in different combinations to see how the traits were inherited. They found that some traits, like days to maturity and grain filling period, are controlled by the genes from both parents, while others, like plant height and grain yield, are influenced more by the interaction of the parents' genes. They identified specific parent plants that are good at passing on desirable traits, and found the best hybrid combination for high grain yield.