Some Micromorphological Features Of Atocion Lithuanicum (zapaŁ.) Tzvel. And A. Armeria (l.) Raf. Of Ukrainian Flora
Abstract
V. O. Martynyuk, N. I. Karpenko, O. M. Tsarenko
Atocion lithuanicum (ZapaÅ.) Tzvel. (basionym Silene lithuanica ZapaÅ.) is an endemic species of the Polesie, related and morphologically similar to A. armeria (L.) Raf., which naturally occurs in Central and Southern Europe, but is widely cultivated. In Ukraine A. lithuanicum is considered as separate species and included in different issues of nature conservation, but in Europe it is listed as synonym or variety of A. armeria. Thus, the purpose of our investigation was to examine micromorphological features of these taxa to distinguish them. Pollen grains, seeds and leaf surfaces of both Atocion lithuanicum and A. armeria (L.) Raf. were investigated by scanning electron microscopy. Palynological distinctions between these taxa are associated with the ultrastructure of pollen grains, such as margin of a pollen (smooth or undulate), diameter of pores (3,04-5,22 (3,96±0,57) or 2,62-4,15 (3,47±0,32) µm), microechinate number on the pore (11-20 (25) or 7-14), exine ornamentation (acute, broadly conical spinule or obtuse spinule) and perforation diameter (0,1 or 0,2-0,3 µm). Seed characteristics such as dimensions (350-570 Ñ 450-630 (468,78±49,2 Ñ 544,84±51,39) in A. lithuanicum or 480-670 Ñ 600-800 (595,67±48,04 Ñ 706,67± 50,26) µm in A. armeria), shape (reniform-circular or reniform-triangular and reniform-circular), dimensions of exotesta cells in distal row (69-160 Ñ 13-28,6 (116,52±21,9 Ñ 20,72±3,99) or 95,6-202,7 Ñ 7,8-40,5 (143,31±27,3 Ñ 28,76±5,05) µm), the number of anticlinal wall teeth (15-24 or 19-29), papilla presence on periclinal wall of lateral and dorsal surfaces (common absent or scarce weakly expressed in A. lithuanicum or usually strongly expressed in A. armeria) also differ these taxa. Epicuticular wax projections are of different size and shape even on the same lamina, so no significant differences in the leaf surface microcharacteristics were observed. Thereby, new micromorphological distinctions associated with the ultrastructure of pollen grains and the seeds were demonstrated, which allows to distinguish these taxa.
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