Environmental stress recovery of horned poppy (Glaucium spp.) using growth regulator treatments

Plant species and cultivars within a species vary in their recovery from salinity and drought stresses when conditions become more favorable. Water conservation, especially in arid and semiarid regions of the world, is a necessity. Plant species, and cultivars within a species, vary in their salinity and drought tolerance. These variations are the result of variations in genes relating to drought tolerance mechanisms and their interaction with the environment. In order to reduce water usage, it is important to understand the mechanisms of plant adaptation to salinity and drought stresses. Many reports have confirmed the internal modification in growth regulator in terms of types and concentrations under stress conditions. Externally applied growth regulator amendments affect the internal balance of growth regulator and can help the plant to regrow and recover from stress. Horned Poppies (Glaucium SPP.) are members of the Poppy family, Papaveraceae, that are native to the Mediterranean and Middle East regions.;The objectives of this study were to 1) determine whether applications of Abscisic acid (ABA), salicylic acid (SA), fusicoccin (FC), and ethephon (E) could promote Glacium spp. Growth and recovery from salinity stress; 2) determine whether applications of (ABA), (SA), (FC), and (E) could promote Glacium spp. growth and recovery from drought stress; 3) determine the most effective concentrations of each growth regulator in the recovery of the stressed plants; 4) evaluate the recovery degree from salinity and drought stresses among the common Horned Poppy species that are available at Denver Botanic Gardens, G. flavum, G. corniculatum, G. grandiflorum and G. acutidentatums ; 5) determine which evaluation criteria are associated with superior recovery rate; 6) confirm selection criteria for evaluation of salinity and drought tolerance in Horned Poppy species; 7) test the change in the concentration of the internal growth regulator under stress conditions and during recovery in those Horned Poppy species studied.;Glaucium spp. under salinity and drought stress exhibited a positive response to growth regulator treatments in terms of improving leaf characteristics, plant height, overall plant quality (attractiveness), TNC, and water use efficiency. G. flavum showed greater tendency to recover from drought stress at all growth regulator treatments when compared to the other species tested. The treatment of 2 mM ABA is recommended to improve the recovery rate of Glaucium spp. under salinity and drought stress. During stress, internal ABA accumulation was evident to cope with stress conditions. During recovery, when the circumstances were favorable for growth, other groups of growth regulator that are needed for accelerated cell division, enlargement and growth such as auxins, gibberellins, and cytokinnins were abundant. (Abstract shortened by UMI.).