Fig. 10. RNA blot analysis of root cold hardiness gene expression of six alfalfa cultivars with contrasting fall dormancy and winter hardiness. Twenty micrograms of total RNA was loaded per lane and blots were hybridized with three ³²P-labeled cold-acclimation responsive cDNAs: bN-1 12a3, RootCar1, and bC2E 40a. Alfalfa plants were cut in October (C) or uncut (U). Roots were sampled at the time of defoliation in October or after a period of cold acclimation in December. Included in the study were the dormant cultivars ‘53Q60’ (Q60) and ‘54H69’ (H69), the nondormant cultivar ‘5939’, and three semidormant germplasms: 96P51PSI (P51), Z57NO2 (NO2), and 96P55PSI (P55).