Top Cross Analysis of Maize (Zea mays L) Inbred Lines for Some Agronomic Traits in Central Rift Valley of Ethiopia

Abstract

Drought stress tolerant maize breeding program of Melkassa Agricultural Research Center (MARC) which is experimental farm of Ethiopian Institute of Agricultural Research (EIAR) in collaboration with CIMMYT has developed a large number of drought stress tolerant and/or early maturing elite maize inbred lines. The effort is aimed at identifying better combining inbred lines for the development of hybrids for drought stressed areas of the country as no hybrid maize variety has been released for this target area so far. To initiate effective hybrid breeding program, information on the combining ability of inbred lines is an essential and critical factor. In the current study, therefore, an attempt was made to generate information on 24 elite maize inbred lines crossed to two testers in line x tester mating fashion and evaluated the GCA and SCA effects of the inbred lines and the test cross performance of the hybrids for  traits like date of emergence, anthesis to silkikng interval, days to maturity, number of kernels per row, number of rows per ear, stand count after thinning and biological yield. The genotypes were planted in 6x9 alpha lattice design replicated twice. Analysis of variance indicated significant mean squares due to genotypes for days to maturity, biomass yield, number of ears per plant and number of kernels per row which could be utilized for future evaluation for possible release or used in maize breeding activities. Highly significant differences were noticed among the crosses for biomass yield, number of kernels per row, number of ears per plant, number of rows per ear, indicating that the presence of numerous variations among each other for these traits. Similarly, mean squares due to SCA were highly significant for biomass yield, and number of kernels per row, and number of rows per ear.

Keywords: inbred lines, GCA, SCA