Comparative pollen morphology and its systematic implications in Resedaceae in Iran

The pollen morphology of Resedaceae in Iran has been studied using light and scanning electron microscopy and described in detail for the first time. Although most of the species had prolate or perprolate pollen grains, variation was observed in other diagnostic pollen characters. Based on exine ornamentation, the pollen grains could be divided into six main types: reticulate, macroreticulate, microreticulate, reticulate-striate, rugulate and perforate, and eight subtypes. In addition, the studied species varied in pollen size, shape in equatorial and polar views, aperture features and ornamentation, representing Resedaceae as a eurypalynous family. The largest pollen grains belonged to Reseda lutea L., while R. aucheri subsp. rotundifolia (Kotschy ex Mull.Arg.) Rech.f. had the smallest ones. Furthermore, species of Ochradenus, Oligomeris and Reseda showed diagnostic palynological characteristics that may provide a better understanding of the taxonomy of Resedaceae. A dichotomous key based on pollen morphology to the 27 Resedaceae taxa native to Iran are also presented.

Automated summary

The pollen morphology of Resedaceae in Iran was studied in detail for the first time, revealing variation in pollen grains and providing a dichotomous key for distinguishing the 27 native species. This study identified different types of pollen grains and diagnostic pollen characteristics among species, contributing to a better understanding of the taxonomy of Resedaceae.