Figure 4.

Seed Dormancy.

Freshly harvested seeds were plated on ABA-free medium and incubated directly (without cold pretreatment) at 21°C with a 16-hr-light photoperiod. The number of germinated seeds (with fully emerged radicle tip) at a given time was expressed as the percentage of the total number of seeds plated (100 to 200). In simultaneous experiments in which seeds from the same batches were first chilled for 4 days at 4°C in darkness to break dormancy, all genotypes displayed 100% germination after 5 days at 21°C (data not shown).

(A) Seeds of the Ler wild type (open squares), ctr1-10 (filled diamonds), and ein2-45 (filled circles).

(B) Seeds of the Col wild type (open squares), ctr1-1 (filled diamonds), ein2-1 (filled circles), and etr1-1 (filled triangles).