Germination of seeds at different days of afterripening
(DAR) or nonafterripened caryopses and the characteristics shattering, awn, and black hull and red pericarp colors in weedy strain-derived B[C.sub.1][F.sub.1] populations.
This Type 2 response (Vegis, 1964) of afterripening and germination relative to temperature is an adaptation to a cold unfavorable season (Baskin et al., 1993).
After selection of seeds, afterripening and stratification must occur.
Dominance of seed dormancy varied with the period of afterripening and the measurement.
In contrast with seed morphological or yield traits, research on seed dormancy is more difficult because the phenotype is strongly affected by the type of dormancy, the dormancy measure, and the duration of seed afterripening.
Our data indicated that switchgrass seeds within a population have varying degrees or depths of dormancy, or "offness", because they need varying stratification and/or afterripening times to be released from dormancy.
Afterripening influenced the reversion of stratified seeds, that is, the effect of afterripening and stratification was additive.