Combining ability and heterosis for maize grain yield and some agronomic characters [electronic resource].

Includes references.

The present study was carried out at the Experimental Station Farm, Faculty of Agriculture, Mansoura University, Dakahlya Governorate, during the two successive seasons of 2011 and 2012 to determine general, specific combining abilities and heterosis for grain yield and yield associated traits by crossing 6 inbred lines of maize in a half diallel mating design. Fifteen F1 single crosses with their parents were planted in a randomized complete block design with three replicates. Results shdwed that mean squares of crosses were significant for all studied traits i.e. number of days to 50% tasseling and silking, plant height, number of rows/ear, number of grains/row, 100-grain weight, grain yield/plant and shelling percentage. The analysis of variance revealed highly significant mean squares of general combining ability (GCA) and specific combing ability (SCA) for all studied traits, indicating the importance of both additive and non additive genetic effects for these traits. GCA/SCA variances ratios were found to be greater than unity for number of days to 50% tasseling and silking, plant height and 100-grain weight, indicating that the additive and additivexadditive types of gene action were greater importance in the inheritance of these 4 traits. Best GCA effects for earliness traits,(number of days to 50% tasseling and silking) achieved inbred lines P4 (Inb.173) and P5 (Inb.174), for plant height were P1 (Sd63), P3 (Inb.19), P4 (Inb.173) and P5 (Inb.174), for number of rows/ear were P1 (Sd63), P3 (Inb.19) and P4 (Inb.173), for 100-grain weight was P1 (Sd63). Inbred lines P1 (Sd63) and P2 (Sd7) showed best GCA effects for grain yield. Also P2 (Sd7) and P6 (Inb.170) showed best GCA effects for shelling percentage.

Summary in Arabic.

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