Estimates of Genetic Variance Parameters and General and Specific Combining Ability of Morphological Traits, Yield and Yield Components of Maize Hybrids in Normal and Salt Stress Conditions

In order to estimate the components of genetic variance and general and specific combining abilities of maize lines, an experiment was done using 8 S6 inbred lines as female parents and 2 male inbred lines as testers consisted of K1264/5-1 (early mature) and K3615/1 (late mature) using line by tester mating design based on randomized complete block design with three replications in two different conditions (Salt stress with Ec=5 dsm-1 and non-salt conditions) in research field of graduate university of advanced technology (Kerman, Iran) in 2014. Analysis of variance results showed significant differences among inbred lines for some of measured traits in both salt and non-salt conditions. Significant differences observed for line × tester mean-squares in non-salty condition for all measured traits except days to silking and physiological maturity. In salt stress condition, just for leaves number per plant and days to silking, line × tester effects were not significant. Additive variance for days to silking and physiological maturity in non-salt condition was more than dominant variance, therefore the additive to non-additive variance ratio was more than 1 and indicating emphasis on this matter too. Inbred line L6 had a significant positive GCA and the highest grain yield with 1455.785 and 789.107 kg/ha in non-salt and salt stress condition, respectively. The crosses (L4×T1=428.460 and L7×T1= 438,345) in non-salt condition and (L3×T1=438.345) in salt stress conditions had a positive significant specific combining ability. Finally, from all existed variation, the lines and line × tester effects were more important than tester effects that indicates transmission of diversity from lines to hybrids.