The influences of simulated moisture stress conditions and osmotic substrates on germination and growth of cultivated and wild safflowers

Abstract

SUMMARYComparisons were made between cultivated safflower varieties (Carthamus tinctoriusL.) and six wild ecotypes (C. oxyacanthaBieb.) for their tolerance to simulated drought conditions. Plant characteristics of the wild strains were noted and soil samples from their collection sites were analysed for the electrical conductivity of the saturation extract. Polyethylene glycol 6000, mannitol and sodium chloride were used as osmotic substrates to prepare aqueous solutions having 0, 1, 2, 5, 8, 12, 15 and 18 atm. of osmotic potentials (OP). The influences of treatments were studied on seed germination, shoot length and fresh and dry weights of shoots and roots of seedlings.Increased OPs progressively delayed and reduced seed germination, shoot length and fresh and dry weights of seedlings. Shoots were, however, more adversely affected than roots. Wild ecotypes were apparently more sensitive to high OPs than the cultivated varieties.