An Indoor Screening Method for Reduced Fall Dormancy in Alfalfa

Abstract

Fall dormancy (FD) is a determinant component of alfalfa yield in northern climate, but selection for that trait is often done at the expense of freezing tolerance. Field selection for low dormancy is a tedious process that depends on unpredictable fall conditions to identify less dormant genotypes. Here we describe two screening methods for low dormancy in alfalfa which can be entirely performed indoor. Both methods rely on plant exposure to a critical photoperiod during four weeks to discriminate plants according to their FD level. One method also includes successive freezing stress to simultaneously improve freezing tolerance (TF) and FD. These approaches can be integrated in a recurrent selection program to produce populations combining reduced FD and high TF.