Abstract: The onset of flowering is decisive to the reproductive success of plants.
The objectives of this study were to characterize the phenotypic variation in
heading date and estimate its heritability in segregating populations of oat
(Avena sativa L.). F2 and F3 generations of two large populations, derived from
crosses ‘URS Taura × Leggett’ and ‘FL0206B-S-B-S1 × UFRGS 078030-1’, were
evaluated. A wide phenotypic variation in the number of days to heading was
observed in both populations. Heritability coefficients of 0.68 and 0.46 were
estimated for the ‘URS Taura × Leggett’ and ‘FL0206B-S-B-S1 × UFRGS 078030-
1’ populations. Our results demonstrate that genetic differences derived from
parents in response to photoperiod and temperature explain most of the phenotypic
variation in heading date of oat populations. Understanding genetic
and environmental effects on flowering expression is essential to increase the
response to selection for well-adapted and high-yielding oat cultivars.