Effect of light and temperature on germination of two accessions ofLimnanthes alba seed

The effect of light and temperature on germination of two accessions ofLimnanthes alba Benth. seed, a potential source of seed oil, were determined. Seed were germinated on a two-way thermogradient plate and in plastic dishes. Temperatures on the thermogradient plate ranged from 5 to 25 C and the temperature gradients were changed on an 8–16 hr cycle. Germination occurred over all treatments when averaged over a constant temperature range of 5 to 17 C. However, maximum germination at constant temperatures occurred at 9 to 13 C. Light suppressed germination on the thermogradient plate at temperatures which were not optimum for germination. Maximum germination and seedling growth were observed at an alternating temperature of 10 C for 16 hr and 15 C for 8 hr in continuous dark conditions.