GENOTYPE X ENVIRONMENT INTERACTIONS IN PROGENY FROM A BARLEY CROSS .1. PATTERNS OF RESPONSE AMONG PROGENY LINES FOR GRAIN-YIELD AND TIME TO ANTHESIS

Barley progeny lines (201) derived from F2 plants of the cross cv. Triumph x cv. Grimmett were evaluated at 7 environments in Queensland. Cluster analysis and principal component analysis were used to examine the variation in response for grain yield. The relationship between days to anthesis and these responses was investigated. The variance component for genotype x environment (GE) interaction for grain yield was of similar magnitude to that for line main effects. Groups of lines formed using cluster analysis exhibited substantial differences in ranking across environments, indicating that selection would be affected by choice of test environments. The components of grain yield, harvest index (HI), and total dry matter (TDM) had large variation for GE interaction. However, for days to anthesis, the variance component for GE interaction was small compared with that for the line main effects. There were significant differences in mean days to anthesis for groups of lines that were classified on the basis of grain yield. Early flowering was associated with high grain yield in some environments but with low grain yield in the 2 irrigated environments. The first component from principal component analysis of grain yield was only weakly related to days to anthesis. This component appeared to be related to performance in favourable environments, suggesting that an important source of variation in grain yield among the progeny lines was associated with their responsiveness to favourable conditions.