Heterosis and Combining Ability for Yield and Quality Characteristics of Chinese Corn (Zea Mays L.) Hybrids

by Open Science Repository Agriculture
(December 2013)

Abstract

This study was conducted to determine the heterosis and combining ability of seven maize genotypes. Analysis of variance showed the presence of significant heterosis for all the traits evaluated

Grain yield showed high relative mid-parent heterosis that varied from 142.30 to 328.77%. Better-parent heterosis for grain yield varied from 130.00 to 301.51% and standard heterosis ranged from -26.50 to 34.37. Quality characteristics such as protein, fat, fiber and starch contents exhibited significant to highly significant variations among the cross combinations. Variable better parent heterosis was obtained for protein and starch contents. Variances due to general combining ability (GCA) and specific combining ability (SCA) were highly significant for all the traits studied except in plant height. Thus, both kinds of gene effects were important in controlling the inheritance of all the characters studied.

However, the GCA:SCA ratio mostly favored SCA in most of the traits, indicating the preponderance of non-additive gene effects in the genetic control of the traits. The estimates of GCA effects revealed that four inbred lines were the best general combiners for grain yield and were good to average combiners for most of the yield component as well as quality traits. These parental lines also produced cross combinations that exhibited significant SCA effects for grain yield and quality traits. Variation due to non-additive type of gene action was greater than the variation due to additive type of gene action for most of the economically important traits evaluated.

Keywords: heterosis, GCA, SCA, gene effect, non-additive, combining ability.

Full text

Heterosis and Combining Ability for Yield and Quality Characteristics of Chinese Corn (Zea Mays L.) Hybrids