Indirect selection through traits of higher heritability and of case measurements can result in larger genetic progress compared to using direct selection. This work was performed with the following objectives: (1) to estimative the phenotypic correlations between individual plant grain yield and agronomic traits of importance in the selection of white oat (Avena sativa L.) genotypes; (2) to identify traits that have the higher direct and indirect effects on grain yield; (3) to determine the intensity of association between primary and secondary components of grain yield; and, (4) to evaluate the consistency of these estimates using five oat genotypes crossed in a diallel format. The number of panicles per plant (NPP) showed to be the trait highest correlated with individual plant grain yield (GY) both through single correlations and through direct effects on grain yields. For weight of a thousand grains (WTG) <FONT FACE=Symbol>´</FONT> GY, in most crosses there was no detected association, leading to possible troubles for breeders, since larger grains were not associated to higher yield, except for the crosses UPF16 <FONT FACE=Symbol>´</FONT> UFRGS17 and UFRGS17 <FONT FACE=Symbol>´</FONT> URPel95/015. The trait number of grains per plant (NGP) was directly correlated with GY in all crosses, although the direct effects estimates on GY were negative for the crosses UPF16 <FONT FACE=Symbol>´</FONT> UPF18, UPF16 <FONT FACE=Symbol>´</FONT> URPel95/015, UPF18 <FONT FACE=Symbol>´</FONT> UFRGS17 and UFRGS7 <FONT FACE=Symbol>´</FONT> URPel95/015, indicating that correlations are not the main causes altering GY, which could be explained, in the present work, by indirect effects via NPP and mainly via panicle weight (PW).
Avena sativa L.; heritability; indirect selection
