AGRICULTURAL BIOLOGY, 2016, V. 51, ¹ 5, pp. 696-704 UDC 633.511:632.4:57.044:581.132 ISSN 2412-0324 (English ed. Online) (SEL’SKOKHOZYAISTVENNAYA BIOLOGIYA) ISSN 0131-6397 (Russian ed. Print) ISSN 2313-4836 (Russian ed. Online) doi: 10.15389/agrobiology.2016.5.696rus doi: 10.15389/agrobiology.2016.5.696eng SEED ENCAPSULATION IN CHITOSAN AND ITS DERIVATIVES RESTORES LEVELS OF CHLOROPHYLL AND PHOTOSYNTHESIS IN WILT-AFFECTED COTTON (Gossypium L., 1753) PLANTS N.G. АKINSHINA1, D.K. RASHIDOVA2, A.A. AZIZOV1 1Mirzo Ulugbek National University of Uzbekistan, Universitet-4 ko'chasi, Talabalar shaharchasi, Toshkent shahri, 100174 O‘zbekiston, e-mail n.akinshina@yahoo.com, azazizov@rambler.ru; 2Research Institute of Cotton Breeding, Seed Production and Agrotechnologies (Republic of Uzbekistan), Salar sh., Qibray tumani, Toshkent viloyati, 111218 O‘zbekiston, e-mail еtoile111@yandex.com Acknowledgements: The authors are grateful for technical support and equipment courtesy of the INNO-Concept GmbH (Strausberg, Germany) Received August 9, 2016 A b s t r a c t Chitosan-based biologicals and chemicals have been proved to possess antiviral, antibacterial and antimycotic activity, and be able to stimulate plant immunity. <...> In field trials (Tashkent region, Uzbekistan, 2015-2016) we first evaluated an impact of seed encapsulation with UzChitan, chitosan ascorbate and Cu2+-chelating chitosan synthesized by the authors' method in the Institute of Chemistry and Polymer Physics of the National University of Uzbekistan (NUUz, Tashkent) from waste of silkworm cocoon processing on photosynthetic activity at wilt (Verticillium dahliae) artificial infection and in wilt-free (healthy) crops of cotton (Gossypium L., 1753) variety Sultan. <...> It was found that wilt-affected control plants (non-treated with chitosan derivatives) had higher specific leaf weight (SLW index), their chlorophyll content was reduced and rates of respiration and apparent photosynthesis were depressed in comparison with healthy control plants. <...> Chlorophyll content in leaves did not vary significantly in absence of the pathogen. <...> That corresponds to toxic effect of pathogen which penetrates through roots and goes up into top parts of plants, damages their phloem system, disturbs water transport, and destroys chlorophyll and leaf tissues. <...> Besides, some tendency to respiration rate inhibition was observed for non-treated cotton plants under wilt <...>