THE STRUCTURAL ORGANIZATION OF LEAVES MESOPHYLL AT NAGEIA NAGI (PODOCARPACEAE)
G.K. Zvereva1,2
1Novosibirsk State Pedagogical University, 630126, Novosibirsk, Vilyuyskaya str., 28
labsp@ngs.ru
2Siberian Federal Scientific Center of Agro-Bio Technologies RAS, 630501, Krasnoobsk, Novosibirsk region
Keywords: Podocarpaceae, Nageia nagi, пространственная организация мезофилла, клетки простой формы, Podocarpaceae, Nageia nagi, structural organization of mesophyll, simple-shaped cells
Abstract
The spatial structure of the leaf blade mesophyll of evergreen woody plant Nageia nagi (Thunb.) Kuntze ( Podocar paceae ) is considered. N. nagi leaves are dense, wide, with numerous parallel longitudinal veins. The cell organization of chlorenchyma was studied on transverse and longitudinal sections of leaf blades. The assimilation parenchyma is multi-layered, differentiated and consists of cells of a simple form. It is represented by palisade and spongy tissues, between which there are large elongated median cells across the leaf, or cells of an intermediate type, interacting with each other by small end surfaces. The palisade cells are cylindrical or cone-shaped forms, the cells of the spongy parenchyma differ mainly in size along the leaf, among them are narrow, thickened and close to globular. Hydraulic compartmentalization in the leaves of the N. nagi can be caused by the presence of three types of mesophyll cells. The considerable volume of chlorenchyma in the leaves is occupied with median cells, mainly through which water is transported from conducting bundles to the spongy layer and stomata located on the lower surface. The part of these cells can perform water reserving function. The spatial organisation of mesophyll of multinervate leaves N. nagi largely resembles of that in uninerved leaves of conifers with simple-shaped cells.
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