Pollen morphology, viability, and germination of Tanacetum vulgare L

Abstract

The pollen morphology of aromatic Tanacetum vulgare L. (Asteraceae), which has wide horticultural and medicinal uses, was examined using light microscopy and scanning electron microscopy. The investigation revealed that pollen grains are radially symmetrical, isopolar, spheroidal, tricolporate, and echinate-perforate. Average pollen length was 21.32 ± 1.12 μm, whereas average pollen width was 20.04 ± 0.98 μm (length:width ratio 0.94). Spine length was 2.72 ± 0.29 μm. Average distance from the spines was 7.15 ± 0.31 μm. Pollen exine consisted of 1-3 pores. Pori are elongated and also with a distinct margin. The porus latitude is smaller than the colpus latitude. One to three perforations were noticed on 1 μm2 of exine. Fluorescein diacetate was used to assess the viability of T. vulgare pollen. The effect of sucrose (1%, 5%, 10%, 20%, and 30%, w/v) on pollen germination and tube growth was evaluated. Overall, the inclusion of sucrose in the medium improved both pollen germination and tube growth. Also, pollen nucleus status was determined. Binucleate and trinucleate mature pollens were observed. Overall, the palynological features of this species may be helpful for further taxonomical and pharmaceutical investigations.