Abstract:

The objective of this study was to estimate combining ability for protein, starch and oil content. 10 elite inbred lines of normal maize were used as parents in a complete diallel mating design. Parental lines and their 90 reciprocal crosses were evaluated in field trials conducted in Beijing and Shanxi in 2002. In the materials under studied, mean squares duo to general combining ability (GCA) and specific combining ability (SCA) were highly statistically significant for three traits. Furthermore, GCA mean square was found to be much larger than SCA for these quality traits, suggesting that they were mainly controlled by additive gene action in their inheritance. Results of correlation analysis showed that per se performance of the hybrid was positively related to the mean GCA of two parents and SCA, while a stronger correlation was found between the hybrid and the mean GCA of two parent, with r-values of 0.708**, 0.756** and 0.772** for protein, starch and oil, respectively, indicating that increased GCA of the parents is more important for improving the grain quality of the hybrid. Estimates of GCA effects revealed that inbred lines BT1 and E28 had higher GCA values for protein; Ye478, Chang 7-2, Ye107 and 48-2 for starch, and E28, Huang C and P138 for oil content among the 10 inbred lines.