Variances, Correlations and Path Coefficient Analysis for Half Diallel Crosses in Maize (Zea mays L.) and Its Effects by Plant Spaces

خالد محمد داؤد الزبيدي1 احمد هواس عبدالله أنيس2 داؤد سلمان مدب العبيدي3 محمد عبد حرجان الجنابي4

Abstract

       Number of days to 50% tasseling and silking, plant height, leaf area, number of rows per ear, number of grains per row, 300 grain weight and grain yield per plant  of 21 F1 populations derived from half diallel cross among six inbred lines of maize (SH, IK8, IK58, OH40, UN44052 and ZP105) were studied. The inbred lines and their hybrids were planted at Beji (Salahuldin Governorate) during autumn season of 2013 at three spaces between plants (15, 20 and 25cm) using RCBDesign with three replications. Genotypic (additive and dominance), phenotypic and environmental variances, narrow and broad sense heritabilities and expected genetic advance were estimated at each space, and path coefficient analysis was used at each space to partition phenotypic correlations between yield and other traits to direct and indirect effects and estimation relative  importance of each trait. The environmental and dominance genetic variances were significant from zero for all studied traits at the three spaces. The additive variance the the spaces 15 and 20 cm was not significant from zero for number of days to 50% tasselling and silking while it was significant for other traits at the same spaces and for all traits at 25cm. The dominance variance was higher than additive variance and had more effects for all traits. Phenotypic correlation of grain yield per plant was positive and highly significant at 15cm for 300 grain weight, number of grains per row and plant height, and significant with leaf area. At 20cm, its correlation was highly significant with 300 grain weight and number of grains per row, while at 25cm was significant only with plant height. It was shown that the traits 300 grain weight and number of grains per row had positive and high direct effects at the three spaces on grain yield per plant, and also the same two traits showed high values  of broad sense heritabilities and low for narrow sense and genetic advance as percent of trait mean. The values of determination coefficient for the two traits were (0.617 and 0.707), 0.353 and 0.492) and (0.297 and 0983) at the spaces 15, 20 and 25cm between plants, respectively, while the relative importance of both on yield were 7.841, 6.604 and 6.798% at the three spaces, respectively.