Heterosis and combining ability for yield and its components through diallel cross analysis in maize (Zea mays L.)‎

الملخص EN

Diallel crosses, without reciprocals, among eight new yellow maize inbred lines derived from different maize populations were made in 2012 season at Experimental Farm, Faculty of Agriculture, Minufiya University at Shebin El- Kom.

The resultant 28 crosses along with the check hybrid SC166 were evaluated in a randomized complete block design with three replications conducted at two locations, i.e.

Shebin El-Kom and Alexandria in 2013 season.

The results indicated that mean squares due to crosses, G.C.A.

and S.C.A.

were highly significant for all studied traits indicating the importance of both additive and non-additive gene effects in the inheritance of these traits.

The parental inbred lines P1, P6 and P7 had significant positive G.C.A.

effects for grain yield.

For other traits, the best general combiner were P5 and P7 for earliness and P4 for both shorter plants and lower ear placement.

The best cross combinations for earliness were P2 × P4 and P3 × P6.

Concerning plant and ear heights, the crosses P1 × P2, P5 × P7 and P5 × P8 had the shortest plants with the lowest ear placement.

The crosses P1 × P6, P2 × P4, P3 × P6 and P7 × P8 had the best S.C.A.

effects for grain yield.

The crosses P1 × P6 and P3 × P6 significantly out yielded the check hybrid SC166.

The crosses P1 × P6 and P3 × P6 observed the highest percentage of heterosis for yield over the check variety.

Six crosses showed significant negative heterosis for days to 50% silking.

For short plant and lower ear placement, the crosses P1 × P2 and P3 × P4 showed negative heterosis.

These promising crosses may be released as commercial hybrids after further evaluation