Adaptation to reductions in chilling availability using variation in in .

Winter annual crops are sown in late summer or autumn and require chilling to promote flowering the following spring. Floral initiation begins in autumn and winter, and in winter oilseed rape (OSR), continued chilling during flower development is necessary for high yield potential. This can be a problem in areas where chilling is not guaranteed, or as a result of changing climates. Here, we used chilling disruption and low chilling to identify loci with the potential to increase chilling efficiency in winter OSR. We report that time to flowering and yield potential under low chill conditions are affected by variation at the gene, a component of the plant PAF1c complex. We show that increases in winter chilling given to developing flowers can improve seed yields and that loss of function of leads to early flowering in and and an increase in seed set where chilling is limited. Because is known to specifically target the () gene in Arabidopsis, we propose that variation at is useful for breeding modifications to chilling responses in polyploid crops with multiple copies of the gene.