FEATURES OF THE MESOSTRUCTURAL ORGANIZATION OF THE LEAVE AND THE ANATOMICAL STRUCTURE OF THE TOBACCO STEM UNDER THE ACTION OF GROWTH STIMULATORS

Tobacco plants of Ternopil 14 variety were treated with growth stimulants 1-NAA, GA3 and 6-BAP in the budding phase. Under the influence of growth stimulants, tobacco leaf blades thickened due to the growth of chlorenchyma. The greatest increase in leaf thickness was found after the application of GA3. 1-NAA and GA3 increased the volume of columnar parenchyma cells. The size of the cells of the spongy parenchyma under the action of growth regulators did not change significantly. It was found that 1-NAA reduced the number of epidermal cells and the number of stomata per unit abaxial surface of the leaf, and under the action of 6-BAP, these indicators increased authentically. GA3 increased the number of epidermal cells and decreased the number of stomata. All growth stimulants reduced the area of the stomata. Growth stimulants thickened the collenchyma layer and increased or did not change the size of sclerenchymal fiber cells. The thickness of the shells of sclerenchyma cells increased significantly only with the use of 6-BAP. Under the action of other growth stimulants, this indicator had only a tendency to increase. 1-NAA and 6-BAP increased the thickness of the secondary layer and decreased the primary periderm. Under the action of GA3, the layers of the primary and secondary periderm became thinner. The drugs increased the thickness of the xylem and the diameter of the largest vessels.