ESTIMATING OF GENETIC PARAMETERS AND CONSTRUCTION OF SELECTION INDICES FOR EXOTIC AND ENDOGENOUS MAIZE GENOTYPES.

Abstract

Selection index state how and which trait should be chosen.21's maize genotypes sown at the field crops stationcollege of AgricultureUniversity of Tikrit,using Randomized Complete Block Design with three replications to estimate genetic parameters for grain yield(x1) and it's components :ear. plant-1(x2),rows.ear-1(x3),grains.row-1(x4),500-grains weight(x5) and grain percentage(x6)as well as distinguishing superior selection index and genotype. The results showed significant differences among genotypes for grain yield,ears.plant-1,grains. row-1 and 500 grains weight. Genetical and environmental variances were closely in most studied traits, while positive highly significant genetic correlations were found between grain yield and each no.ears.plnt-1 and 500grains weight. Also no.ears.plant showed high significant correlation with 500grains weight and grain percentage. While phenotypic correlations were neglected and mostly negative except positive significant correlation between grain yield per plant and grain percentage .Low values of H2b.s. in most traits companied with moderate percentage of genetic advance(21.32 ,18.94%)in ears.plant-1 and grain yield respectively. Responses for combined selection were more important especially in ears.Plant-1and 500 grains weight that can be taken as important traits composed the superior selection index.The best genotype was (DKC6677)followed by Tauste,NK sweedish,Hay al-shemal, and Drachma as compared with the other genotypes.Predomenant genotypes can be used for improving grain yield and its components by using the best specific selection index(I125) .