To determine the response of seeds to cold stratification, fresh
seeds were mixed with moist sphagnum moss (as described
above) and placed in darkness for 0 (control), 4, 8, 12 and 16
weeks. After each treatment, seeds were incubated for 12 weeks
in light at 25/15 C as described above. The control was fresh seeds
incubated at 25/15 C throughout the experiment. Three hundred
seeds each cold-stratified at 5 C for 4, 8 and 12 weeks and 200
seeds with radicles emerged were immediately frozen in liquid
nitrogen and stored at 80 C until further analyses could be
performed.