CHOOSING THE BEST PARENTS FOR A BREEDING PROGRAM FROM AMONG EIGHT OAT CULTIVARS CROSSED IN DIALLEL
Twenty-eight oat hybrids from a diallel cross of eight parents were evaluated using field-grown F2 (1970) and F3 (1971) bulks at competitive spacing and with different exposures to moisture stress. These were compared with irrigated, space-planted F1’s. Short, stout straw was negatively correlated with grain yield. Correlations of 1,000-kernel weight and panicle number with other traits changed sharply from year to year. General combining ability (GCA) effects showed that Astro, Clintford and Purdue 6316 were outstanding parents for desirable stem type, as were Gemini and Clintford for 1,000-kernel weight and Gemini, Kelsey and Marino for yield. Index selection among the progenies using four traits gave largely contradictory results for the 2 yr, but GCA effects of the index values point to Astro and Clintford as the best all-round parents. Data from F1 spaced plants in an optimum environment were useful for predicting field responses in the year when no moisture stress occurred during grain filling, but not in the year with such stress. Midparent values for grain yield were highly correlated with progenies’ yields only in the year with no moisture stress during grain filling.