Analysis of the genetic and environmental factors influencing grain quality of oats (PhD)

Abstract

Grain quality of oats is important to meet the requirements of the milling industry and to enhance the value of the crop for the grower. Developing oat varieties with high milling quality is constrained by a lack of detailed information on how genetic differences and environmental and management factors impact on grain quality. Focussing on key milling quality characters, i.e. specific weight, kernel content, hullability and thousand grain weight, four winter oat varieties (Gerald, Mascani, Tardis and Balado) were grown under conventional and organic regimes at six different geographical locations in 2012-13 and 2013-14. In addition, grain yields and oil, protein and β-glucan content of the groat were determined. The length, width, area, roundness and weight of the grain and groat, were measured using non-destructive methods. The influence of environment, management conditions and genetic differences on grain quality parameters, were determined. The results were statistically significant for grain and groat area, length and width, for both environment and genotypes (p-value <0.05). Grain yield however, were only significantly different between environments and not between varieties. Negative and positive correlations were found between grain size and shape with kernel content, hullability and thousand grain weight when studying each of the genotypes, showing the influence of grain and groat area (mm²), length (mm) and width (mm), over each quality parameter. The variability found in this project, between environments, years and genotypes suggest that locally adapted varieties could perform better. Therefore, niche-matching varieties according to historical performance of local environments rather than overall performance of the variety would allow reaching higher grain quality parameters for end-users and  milling industry requirements. Follow on investigations will examine the effect of nitrogen fertilisation on milling quality traits as well as using a mapping population to determine their genetic basis. The results obtained in this research will be used to develop new varieties for the milling industry, by the farmer to assess quality on farm prior to marketing and by the plant breeder in selection programs, where genetic improvements in milling quality may be made more precisely and rapidly than previously.