Multifunctional biopreparations and complexes based on microorganisms and chitosan increase diseases resistance, productivity and leaf photosynthetic pigment contents in spring soft wheat (Triticum aestivum L.)

The application of useful microorganisms and biologically active molecules lies at the basis of the modern concept of agroecosystems phytosanitary optimization. The increase of the protective properties of preparative forms, which include phytopathogen antagonists and chitosan, is due to the ability of chitosan polysaccharide to induce systemic plant disease resistance. In addition, multifunctional compositions with multiple action mechanisms, effective against a wide range of phytopathogens, can positively effect on the functional state of plants, including their photosynthetic activity, quantitative and qualitative changes in the entire pigment system, which often reflect the nature of adaptive reactions under stress. However, studies of changes in the photosynthetic apparatus in relation to the disease resistance and plants productivity under the influence of such compositions are extremely few. It was shown for the first time that the multifunctional complexes Vitaplan, KZh + Chitosan II and Vitaplan, KS + Chitosan II significantly increase wheat productivity and disease resistance, while the content of chlorophylls a and b in leaves also turned out to be the highest. The ratio of chlorophylls a + b and carotenoids content, which serves as one of the indicators of plant stress resistance, was maximal when using the Vitaplan, KZh + Chitosan II complex. This study aimes to estimate the potential wheat productivity by morphometric indicators of plant development, susceptibility to root rot, brown and yellow rust, powdery mildew, Septoria leaf blotch, and the content of chlorophylls a, b, carotenoids in leaves when using multifunctional biopreparations and complexes combining the useful properties of microorganisms - antagonists of phytopathogens and chitosan as plant disease resistance activator. Seeds of the Leningradka 6 cultivar (k-64900, VIR collection) of soft spring wheat ( Triticum aestivum L.) were treated before sowing with biopreparations based on Bacillus subtilis strains VKM B-2604D and B. subtilis VKM B-2605D Vitaplan, SP, Vitaplan, KZh and the complexes Vitaplan, KZh + Chitosan II, Vitaplan, KS + Chitosan II. In the field during the growing season, plants were sprayed with the same preparations vs. control (without treatment). In general, the used complexes turned out to be more effective than biopreparations by 16.2 %. The multifunctional compositions application significantly reduced wheat plants harm by diseases complex (by 17.9 % at p function show_eabstract() { $('#eabstract1').hide(); $('#eabstract2').show(); $('#eabstract_expand').hide(); }