Sel’skokhozyaistvennaya Biologiya [Agricultural Biology], 2011, № 5, p. 81-85 UDC 635.3:574.45:631.8:577.175.14 A NEW NATURAL STIMULATOR 4-HYDROXYPHENETHYL ALCOHOL EFFECTS ON AMARANTH SEEDS GERMINATION AND PLANT PRODUCTIVITY 1 Institute of Fundamental Problems of Biology, RAS, Moscow province, Pushchino 142290, Russia e-mail: cheredova@mail.ru E.P. Ivanova1, L.L. Kirillova2, L.D. Smolygina1, O.P. Serdyuk1 2 Tula State L.N. Tolstoy Pedagogical University, Tula 300026, Russia Received January 11, 2010 S u m m a r y The results of comparative studying effects of 4-hydroxyphenethyl alcohol — exometabolite of purple bacterium Rhodospirillum rubrum and synthetic cytokinin 6-benzylaminopurine on seed germination, growth, productivity and development of amaranth vegetable form (Amaranthus caudatus L.) and also on the set of their physiological-biochemical parameters are presented. <...> It was established, that seeds treatment with solutions of investigated substances (10-6 М) led to similar positive effects in all studied indices in the plants growing from these seeds. <...> The authors suggest to use the 4-hydroxyphenethyl alcohol as the growth cytokinin-like natural stimulator for improvement of seed grain and plant productivity. <...> Amaranth (Amaranthus caudatus L.) is very popular in Europe as a valuable food culture. <...> Introducing this plant in Russia is complicated by a number of reasons, one of which is a specific ontogenesis: nearly a month after germination, young amaranth plants start the phase of so-called latent growth when aboveground phytomass almost doesn’t grow while the rapid development of a root system (1). <...> In earlier research, the authors have derived this substance from the culture medium of Rhodospirillum rubrum (2). <...> Previously, a specific cytokinin-like action was found in HPEA: it stimulates the synthesis of amaranthine in isolated amaranth seedlings. <...> These data suggest an assumption that HPEA performs cytokinin-like properties on a whole plant as well. <...> Cytokinins perform various effects in plants; they regulate seed germination and ripening (4), stimulate plant growth and development, increase total protein content and activity of a photosynthetic apparatus; along with it, cytokinins specifically increase the activity of nitrate reductase (NR) and help to eliminate adverse effects of stress (5). <...> Stimulatory action of cytokinins improves <...>