Combining Abilities of Main Agronomic Traits of Several Maize Inbred Lines

Thirty combinations were made between 3 inbred lines and corresponding improved inbred lines involving tropical maize germplasm as female parents and 5 inbred lines from other places as male parents with NC Ⅱ mating design to analyze the combining abilities of 10 agronomic characters.The results indicated that:① inbred line4Shad higher general combining ability(GCA) in 100 grain weight and yield per plant,and the combinations made by 4S as female parent had better stability in yield;②75 and 249 were of higher value in dwarf breeding;③improved inbred lines had higher GCA in plant height,ear height,ear width and rachis width than their corresponding inbred lines,while other agronomic characters performed differently according to their genetic background;④most of the agronomic characters of the combinations were affected by both parents′ GCA and SCA,and selection of the combinations with higher yield should be given consideration to both GCA and SCA.