Micromorphological features of pollen grains, seeds and leaf surfaces of Atocion hypanicum (Klok.) Tzvel. and A. compactum (Fisch.) Tzvel

Abstract

V. O. Martynyuk, N. I. Karpenko, O. M. Tsarenko

Based on scanning electron microscopy, ultrastructure of leaf surfaces, pollen grains and seeds have been investigated for two Atocion Adans. species – Ukrainian endemic A. hypanicum (Klok.) Tzvel., and A. compactum (Fisch.) Tzvel., which areal comprises the Balkans, Caucasus and Western Asia. New delimiting micromorphological characteristics, associated with ultrastracture of pollen grains (microechinate number on the operculum: A. hypanicum – 6-15, A. compactum – 11-26) and interporal distance (A. hypanicum – 6.72±1,2 µm, A. compactum – 5.19±1,22 µm), have been designated. A. compactum seeds also clearly differ from A. hypanicum by the papilla presence on periclinal walls of lateral and dorsal surfaces. However, ultrastructure of the leaf surface, including epicuticular wax projections, does not significantly differ between these taxa.