EFFECTS OF DIFFERENT CLASSES OF SURFACTANTS ON GERMINATION OF WHEAT SEEDS DURING WATER DEFICIENCY

Presowing treatment of winter wheat seeds (Triticum aestivum L., cv. Mironovskaya 808) with surfactants indicated that a wide range of nonionic and ionic surfactants are effective in activating germination under conditions of water deficiency. The most effective stimulators of seed germination were Tweens 80 and 85, Spans 80 and 85, CTAB, SDS, and OP-7. No clear correlation was detected between biological activity of the compounds and their relative hydrophoby.Comparison of Spans and compounds synthesized on their basis (Tweens) showed that Spans 20, 80, and 85 (derivatives of lauric and oleic acids) had the same activity as Tweens 20, 80, and 85, i.e., the presence of polyoxyethylene chains in molecules was not necessary for their biological activity. At the same time, Spans 40 and 60 (derivatives of palmitic and stearic acids) were completely inactive, in contrast to Tweens 40 and 60. Nonionic surfactants exerted physiological action at concentrations appreciably higher than the critical concentration for micelle formation (CCM), whereas the activity peak of CTAB and SDS coincided with their CCM. Appreciable phytotoxicity was detected for CTAB. Possible mechanisms of surfactant action on seed germination during water deficiency are discussed in the paper.