COMBINING ABILITY IN MAIZE LINES DERIVED FROM THE FIFTH CYCLE OF STRATIFIED MASS SELECTION

Abstract

The estimation of genetic parameters in maize breeding is of great importance after the application of selection, which allows the breeder to define strategies to take advantage of the expressed genotypic variability. The objective of this research was to estimate the general combining ability (GCA) and specific combining ability (SCA) of eight S1 inbred lines (L) by means of a partial diallel. The 28 direct crosses generated were evaluated in the P-V 2022 cycle, using a randomized complete block design, with four replications, in two locations, under rainfed conditions with an auxiliary irrigation for germination. Lines L2, L3 and L4 showed positive and significant ACG effects for grain yield (GR), indicating that these lines showed a greater effect of additive genes. For flowering variables (male and female), lines L2 and L3 showed positive and significant effects of ACE. Lines L1 and L2 showed positive and significant ACE values for the RG variable. In the genotype-environment interaction, the L2×L4 cross (with positive and significant ACE and ACG effects) was less stable, with higher yield (6.67 t ha-1) and surpassed with 1.36 and 1.4 t ha-1 the controls (V1 and V2), respectively, but more adaptable to the two locations, according to the biplot analysis.