VARIATIONS IN ACCESSIONS OF SUNFLOWER AND SAFFLOWER UNDER STRESS CONDITION

Abstract

Two sunflower i.e., Helio & NuSun, and 2 safflower accessions i.e. Spiny & Non-Spiny differing in salt sensitivity, were examined for compatible solutes and some enzyme activities involved in seed germination i.e. α-amylase, β-amylase and α-glucosidase, under control and different levels of sea salt concentrations i.e. 0, 0.2, 0.4, 0.6 and 0.8% having ECiw = 0.5, 3.4, 6.1, 8.6 and 10.8 dS/m respectively. The inhibitory effects of salts differed among all the accessions tested. In Helio and Non-Spiny cultivars the increase in salt concentration reduced germination percentage and lower relative water content, and also decreased the endogenous levels of proline, total soluble sugars and activities of the main enzymes involved in the germination process. In contrast, seeds of NuSun and Spiny cultivars accumulated higher proline and total soluble sugar concentrations in response to salt stress, which improved their water status and the enzyme activities involved in the process of germination. Differences in response of the different accessions of sunflower and safflower to salt stress may be due to the accumulation of compatible solutes in their seeds