Pollen and seed morphology of Zygophylum fabago and Peganum harmala (Zygophyllaceae) from Bulgaria

Abstract

Scanning electron microscope (SEM) study of the pollen and seed morphology of Peganum harmala L. and Zygophyllum fabago L. (Zygophyllaceae), in native Bulgarian populations, was carried out. Additionally, a light microscope (LM) investigation on pollen grains was made in order to elucidate the peculiarities of the major parameters of pollen surface and size. It was established that pollen grains in Z. fabago are pantoporate. Exine ornamentation is reticulate. The pollen grains of P. harmala are oblate, spheroidal, elongated, oval in shape, colporate, exine striato-rugulate. The seeds of P. harmala are oblong-oval and slightly flattened at the side (incorrect tetrahedral to rhomboid), with a peaked edge, arc-curve laterally. The seed sculpture corresponds to the Tubular to Concave-type, which is characterized by polygonal cells and reticulate tectum. The seeds of Z. fabago are oval-rhomboid in shape. The seed sculpture corresponds to Concave to Convex-type which is characterized with polygonal cells, ranging in size, with cuticular wax folds.