Effect of drought stress and seed size on antioxidant system and seedling traits of lentil accessions from Varzeqan

Drought stress is a major restrain in the growth and yield of lentil plants especially under rain feed areas. One of the problems of semi-arid regions in the world and Iran is poor seedling establishment due to lack of sufficient water. To study the effects of seed size of local genotypes (accessions) of lentil on the germination and seedlings growth characteristics and some related biochemical reactions under drought stress, a factorial based on completely randomized design experiment with 4 replications was conducted in vitro. The treatments were 4 drought (0, -0.4, -0.8, -1.2 Bar) levels and seed size (small- medium, and large). The results showed that the interactions of all measured traits except root length, root dry weight, shoot dry weight, seedling dry weight and superoxide dismutase activity were significant at the level of 1% probability. So that, the small seeds were superior in germination percentage, germination rate, and shoot length compared to the other seed sizes. With the drought intensity of -0.8 bar, the total antioxidant activity, total soluble protein, hydrogen peroxide content and guaiacol peroxide activity were increased. However, for ascorbate peroxide, the increasing pattern was up to -1.2 bar. Seemingly, the small seeds are more tolerable to the drought stressful conditions the germination and the seeds would be more suitable to be employed under the water scarcity conditions.