The role of phytochrome in the control of salt cress seed germination was studied using non-dormant seeds that were imbibed in the dark and then exposed to different combinations of R- and/or FR-light pulses (Fig. 2b, d).
A pulse of R-light and cold stratification stimulated germination of dark-imbibed seeds, while a following FR pulse inhibited germination in a photo-reversible manner (Fig. 2b, d).
Results of repeated pulse treatments (FR/R and FR/R/FR) also indicated the involvement of phytochrome in the control of seed germination (Fig. 2b, d). However, strong continuous
light (more than 32 lmol m-2 s-1) also significantly inhibited seed germination (Fig. 2e).
All seeds germinated at relatively mild light intensity (1–10 lmol m-2 s-1).