HETEROSIS, COMBINING ABILITY AND GENE ACTION USING LINE × TESTER ANALYSIS IN CORN– ANBAR GOVERNORATE

Abstract

Abstract:Eight inbred Lines of maize ware used in this study using line × Tester analysis ,In spring season of 2003, to produce Fifteen f1 crosses . The parents and crosses were sowing in autumn season of 2003 using R.C.B.D. with three replications to determine heterosis , general and specific combining ability effects and gene action . Significant differences were found between parents Lines and their crosses for all traits, the result were showecd that the ctoss ( ZP607×IK8) gave the highest cross vigor in number of rows per ear (26.74%) and grain yield per plant (52.55%) of the better parent . the cross (ZP607×IK8) gave the highest length ear (20.8)cm and number of rowper ear (21.8)rows and grain yield per plant (225.32) gm. . The value of specific combining ability variance were more than the general combining ability variance for all traits indicating the importance of non –additive gene action . This reflects the reduction of the values for all characters and this reflects the reduction of the values of the narrow sence heritability for all characters and the estimates of the average of dominance were exceeded one for all characters except the ear diameter for the degree of dominance less than one. the results indicate that wecan used some inbred Lines could be used in a breeding program to develop new versions of high yield per plant and SCA to produce better grain yield hybrids and most studied traits were under dominance and over dominance gene action .