ANBAR JOURNAL OF AGRICULTURAL SCIENCES

Abstract

A field trial was carried out at Field Crops Research Station of General Board of Agricultural Research, Abu-Ghraib in spring and autumn seasons in 2009. Six inbred lines of maize (Zea mays L)(ABS09-2 وABS09-8و ABS09-14 وABS09-20 وABS09-26 وABS09-32) were crossed in all possible combinations including reciprocal, during the spring season of 2009 to produce 30 F1 cross (diallel and reciprocal crosses). Seed of parents and crosses were grown in a randomized complete block design (RCBD) with three replicates in fall season 2009. The objective of this study was to identify and select superior maize inbred lines based on their performance as well as to evaluate their crosses performance based on results of genetic analysis of combining ability, gene action and estimation of some genetic parameters using the approach of Griffing method 1 with fixed model for plant height, ear height, ears number per plant, ear length, and rows number per ear, kernels number per row, 500-kernel weight and grain yield per plant. Results of statistical analysis indicated that there were highly significant differences among genotypes means for all studied characters. The inbred line (ABS09-8) gave highest for most of studied characters including grain yield per plant (184.07g). In diallel crosses, the cross (ABS-09-32×ABS-09-26) gave mean highest for ears number and grain yield per plant (215.33g),while in reciprocal crosses, the cross (ABS-09-8×ABS-09-14) gave mean higher for most of studied characters, including grain yield(236.33g). Results of genetic analysis showed that (MSgca), (MSsca) in diallel and (MSrca) for reciprocal crosses were high significant in most of studied characters. The inbred line (ABS09-8) was found as the best general combiner effect for grain yield (8.13) and for ears number per plant (0.068). While the diallel cross (ABS09-26×ABS09-32) and reciprocal cross (ABS09-32 × ABS09-26) were found best specific combiner effect in the crosses for grain yield and ears number per plant (21.29, 0.210) (10.17,0.083) respectively. The ratio of the variance component of (σ2gca) to the(σ2sca) for diallel crosses and (σ2rca) for reciprocal crosses was less than 1.0 in all studied characters, except for ears number and grain yield per plant which was more than 1.0 in reciprocal crosses (1.54, 1.12) respectively. The values of (σ2D) were more than that (σ2A) for all characters except for ears number per plant, 500- kernel weight and grain yield per plant, which were less than those in reciprocal crosses, and this reflects the exceeded one for the value of average degree of dominance for all studied characters in both diallel and reciprocal crosses except ears number per plant which was less than 1.0 in reciprocal crosses and 500- kernel weight which was zero. As diallel cross for broad sense heritability it was high and narrow sense was low in diallel and reciprocal crosses for all studied characters except for 500- kernel weight which was a medium value in diallel crosses. As for reciprocal crosses broad sense heritability was high for all studied characters except for ears number per plant and 500- kernel weight which was a medium value, while grain yield was low value. As for narrow sense was low value for all studied characters except for ears number per plant and ear length which was a medium value and500- kernel weight which was high value.