Genetic and environmental analysis of NIR feed quality predictions on genotypes of barley (Hordeum vulgare L.)

Abstract

This study investigated the use of NIR feed quality equations, developed from a multi-cereal calibration set, including barley, on barley breeding lines and commercial cultivars. The resultant predictions were then analysed to ascertain genetic and or environmental affects. The calibrations were developed by a third party, using a NIRSystems 6500 (master) instrument. The barley spectra we used were also from the same model of instrument, which had been spectrally standardised to match the master instrument. The breeding lines and commercial cultivars used were obtained from a field trial series which combined intermediate and advanced breeding lines, grown at 11 environments over two seasons. The results indicated there were significant (P < 0.05) genetic and environmental effects on a broad range of feed quality related traits; including metabolisible energy, digestible energy and apparent metabolisible energy. Other feed traits such as acid detergent fibre, neutral detergent fibre, β-glucan and starch also showed significant (P < 0.05) genetic and environmental affects. There was a high level of heritability for most traits, ranging from 70 to 90%. The results identified a number of strongly correlated traits when analysed by factor analysis. These included starch and the energy traits. There were no strong associations between particular cultivars and the NIR predicted feed traits. The results from this study highlighted NIR equations for predicted feed quality that can provide data to assist selection of barley breeding lines. In addition, the analysis also showed the genetic and environmental effects that could be expected to be observed in a broad range of barley breeding material and commercial varieties. This information can be combined in breeding programs to identify robust barley lines that would be suited to specific animal feed classes.