Genotype-by-Environment Interaction and Trait Associations in Two Genetic Populations of Oat

Ideal milling cultivars of oat (Avena sativa L.) should have high grain yield, groat percentage, beta-glucan, and protein but oil content lower than certain level. The genotype-by-environment interaction (G x E) of these traits and their genetic correlations were studied using two genetic populations ('Goslin' crossed with 'HiFi' and 'Sherwood' crossed with 'HiFi') tested in multilocation trials from 2010 to 2012 in eastern Canada. The results showed limited G x E for all of the quality traits, especially for beta-glucan and oil, and transgressive segregation was observed for all traits in both populations except for groat percentage in the Goslin x HiFi population. The G x E for grain yield was overwhelming, however, suggesting that yield must be selected within subregions. Four unfavorable trait associations were observed, namely, a negative correlation between grain yield and protein content, a positive correlation between beta-glucan content and oil content, a negative correlation between groat percentage and beta-glucan content, and to a lesser extent, a negative correlation between grain yield and groat percentage. However, the magnitude of these correlations was small and breeding lines with good levels of groat, a-glucan, oil, and protein were identified. These lines may be used as parents in breeding superior milling oat cultivars.