Environmental and genetic variation for grain yield and barley malting quality attributes

Abstract

Genotype, environment, and genotype × environment interaction effects for malting quality attributes and grain yield were investigated using breeding lines from the F₂, F₃, and F₄ generations and the parental varieties of 4 barley crosses. There were significant differences between the parental varieties for all attributes studied. Both malting quality and grain yield exhibited a wide range among progenies in all generations. While performance of the parental varieties and progeny for malting quality and grain yield were greatly influenced by environment, performance in one environment was predictive of that in other environments. Only for grain protein content was there evidence of crossover G × E interaction.

Heritability was generally higher for F₃ to F₄ than for F₂ to F₃ for all malting quality attributes. F₃ on F₂ regression per cent heritability estimates for protein content, potential malt extract and grain weight were all highly significant with values generally medium in magnitude. Genetic gain was obtained from selection in both the F₂ and F₃ generations. Heritability and genetic gain varied from cross to cross for diastatic power. Progress from selection for the other quality attributes attests to the potential value of NIT (near infrared transmittance) spectroscopy for predicting potential malting quality.

Heritability for F₂ to F₃ for grain yield was not significant in any cross, indicating selection for yield on the basis of individual F₂ plant yield was ineffective. Heritability for grain yield from F₃ to F₄ was highly significant and medium in magnitude for 3 of the 4 crosses.

The results of this study indicate that good genetic gain could be expected from early generation selection for potential malting quality using NIT spectroscopy and for grain yield using F₃ progeny testing.