Increasing the Efficiency of Crop Selection for Unpredictable Environments

Abstract

A key decision in crop breeding programs designed to improve productivity under variable environments is choosing the environment to use for selection. Productivity of the plants in the selection environment and/or a high correlation between yield in the test and the target environments have been used to identify the most appropriate selection environments. Several alternatives have been suggested. The objective of this study was to compare the relative efficiencies among indirect selection criteria to improve yielding ability in sorghum genotypes in a wide range of environments. Four dryland locations were used to evaluate 200 S 1 families from two random‐mated sorghum [ Sorghum bicolor (L.) Moench] populations (TP24D, which is an early maturing TP24 derivative, and KP9B) during the summers of 1987 and 1988. The relative efficiencies of indirect selection using yield from any single environment or mean yield from all eight environments were low, but when the indirect selection criteria involved yield combinations from stress, intermediate, and nonstress environment— such as mean productivity, rank summation, and selection indices— the relative efficiencies were higher than those using yield form any single environment. Thus, yield information representing the range of environments in the target area should be involved in the definition of the selection criterion to achieve gain in the selection of genotypes for unpredictable environments.