Heterosis in Oats 1

Several attributes were studied in the F 1 and F 2 generations of oat crosses grown in space‐planted nurseries in 1955. The F 1 's of 15 oat crosses and their parents were sown in a randomized complete‐block design with 3 replicates. The plots, spaced 30 cm apart, each contained 5 competitive plants (sown 30 cm apart) upon which measurements were taken for heading date, number of panicles per plant, number of spikelets per primary panicle, plant height and grain yield. In 1957, the F 2 and parent plants were spaced 10 cm apart and measured for the same attributes as the F 1 's. The grain yields of each F 1 exceeded the higher yielding parent. Grain yields in the F 1 ranged from 101 to 130% of the higher parent with a mean for all crosses of 112%. The parent, Victory, produced consistently low yielding crosses. The yields of some crosses in the F 2 exceeded the higher yielding parent and the mean F 2 yields, relative to the higher yielding parent, was 99%. For one cross, the relative yield of the F2 was 120% of the higher parent. Positive heterosis was expressed for number of panicles per plant, and for each cross the heading date of the F 1 was earlier than the midparent. Except in a few crosses, plant height and number of spikelets per panicle in the F 1 's and F 2 's closely approximated the midparents. The correlations of midparental values with Ft and F2 cross means for number of spikelets per panicle, plant height and heading date were all highly significant and above 0.89. For yield, similar correlations were 0.60.