COMBINING ABILITY ANALYSIS FOR GROUP OF PURE LINES AND THEIR THREE-WAY CROSSES IN MAIZE (Zea mays L.)

Abstract

Six pure lines of maize, IK8, ZP-301, ZP-707, UN44052, OH40 and SH and all possible three-way among them were use in this study. Seeds of genotypes (six lines and 60 three-way crosses) were planted at Al-Rahmania, Mosul in 20 July 2012 using randomized complete block design with three replications to estimate variances and effects of all types for general and specific combining ability of parents and crosses respectively, and also to determine genetic performance that control the inheritance of plant yield and some of its components (number of ears per plant, ear length, ear diameter, number of rows per ear, number of grains per row, number of grains per ear and 300 grain weight) using variance components from three-way cross analysis. Variance analysis results of three-way crosses showed the presence additive and non additive effects for all characters, and the additive and epistasis (additive x additive) effects were more important in the inheritance of plant yield, while non additive effects (dominance and epistasis of this type) more important in the inheritance of all other characters, and then the suitable breeding method to improve these characters was the production of hybrid varieties or recurrent selection for specific combining ability. The pure lines ZP-707, UN44052 and SH characterized by significant desirable effects for general combining ability for more number of characters whether used as parents or grandparents. The behavior of hybrids ZP-707x(ZP-301xUN44052), IK8x(ZP-707xOH40), UN44052x(IK8xZP-301), ZP-301x(OH40xSH) and UN44052x(OH40 x SH) was good for grain yield per plant and They can be used in future breeding programs.

Keywords

Maize, analysis