Assessment of Flax Varieties for Drought Tolerance

Abstract

Introduction: Flax (Linum usitatissimum L.) is one of the ancient yields cultivated for dual purposes (oil and fibers). Drought stress plays an important role in the productivity of the flax crop in the world. Methodology: A laboratory experiment on early seedling growth stage was conducted to evaluate the drought tolerance of Asile and Gentiana flax varieties. Three concentrations of polyethylene glycol (PEG10,000) 5, 10 and 15% were used as drought levels compared with the control (0 level). After ten days of cultivation, germination indices were recorded.  Results: The germination percentage was decreased with the increasing of PEG10,000 in both varieties. Highly significant variance was shown in percentage of germination and shoot length between Gentiana and Asile flax varieties. SDS-PAGE banding patterns indicated that PEG10,000 induced the drought tolerant in the varieties which led to the appearance or disappearance of some polypeptides due to water deficit and depending on the flax variety. Isoenzyme activities of polyphenol oxidase (PPO) and peroxidase (POX) did not differ between control and drought stress conditions in Asile, but differed in Gentiana variety. However, the RAPD-PCR assay exhibited polymorphism between the stressed plants and control. A total number of 75 fragments were amplified by seven decamer primers ranged from 90 to 1400 bp. Forty-four alleles were monomorphic bands (58.67%), while thirty-one loci were polymorphic (41.33%). Conclusion: The results showed that Asile (the Indian) variety was more tolerant to drought than Gentiana (the Romanian) variety which had the highest percentage of germination.