Alleviation of Drought Stress in Vicia faba by Seed Priming with Ascorbic Acid or Extracts of Garlic and Carrot

Abstract

THIS STUDY was carried out to assess the harmful effects of drought stress on Vicia faba L. (cv. Giza 716) and to evaluate the role of priming of the seeds in the extract of carrot root, garlic cloves or in ascorbic acid in the alleviation of these harmful effects. Fourteen days old Vicia faba seedlings grown from primed seeds were subjected to water withholding for 14 days (D1) or 22 days (D2), then left to grow till 40 days. The results revealed that the two levels of drought stress significantly decreased shoot height, fresh and dry masses and water content of root and shoot, as well as leaf area, but they increased root length of 40-days-old plants. Photosynthetic pigments (chl a and chl b), chlo a/chl b ratio, photosynthetic activity, sucrose and starch content were also decreased under the effect of both periods of drought stresses. On the other hand, carotenoid contents, the activities of catalase and peroxidase, ascorbic acid, malondialdehyde (MDA), glucose and total soluble protein contents were increased in leaves. Priming of Vicia faba seeds with the extracts of carrot root (Daucus carota L.), garlic cloves (Allium sativum L.) or with ascorbic acid mitigated all of the recorded harmful effects of drought stress,while they decreased carotenoids, activities of catalase and peroxidase, ascorbic acid, MDA, glucose and total soluble protein contents.