YIELD COMPONENTS OF LINES B OF SORGHUM FOR GRAIN WITH DIFFERENT GENERAL COMBINATORY FITNESS

Abstract

At the Experimental Station El Bajío, 27 B sorghum lines were evaluated in a field trial. These lines were previously grouped for their general combining (GCA) in four groups: 6 late maturity lines with good GCA, 7 early lines withgood GCA (7 1 ines), 8 1 ines with intermediate GCA, and 6 lines with poor GCA. Grain yield, length of the biological cycle and leaf area per plant, were obtained from each line. In the first two variables their components were also analyzed. Corre lation coefficients were obtained for all variables among 1 ines within each genotype group.

The highest average grain yield was found for the group in wich late maturity lines with good GCA were involved. In this group, grain yield was associated with high seed number per head (r = 0.79**), high number of primary branches in the head (r=0.73), long gráin fill ing period (r=0.97**), and more days to physiologic maturity (r=0.96**). In the other groups, there were not consistent significance for the correlation coefficients among grain yield and its components.