Fig. 1

Experimental design and sampling schedule for SD (short day) experiment (11 h light; 13 h night). Untreated control seedlings (green) were kept under natural light conditions indoors and outdoors during the experiment. For the remaining seedlings, SD treatment started on July 15, 2013 in greenhouse for all SD treatments. Seedlings were divided into four batches and subjected to four different SD treatment periods: 7 (orange), 14 (purple), 21 (blue), and 28 (red) days. Following treatment, half of each batch was moved outdoors and the other remained indoors, all exposed to natural day length. Samples for molecular test of dormancy induction were taken each week during the SD treatment period followed by a final sample on Aug. 26 (indicated by open circles). Samples for freezing tolerance (ColdNSure™) were collected at four different occasions: Sept. 9, Sept. 23, Oct. 9, and Oct. 23 (indicated by solid circles). Samples for determination of DMC were taken only on Oct. 23