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

Abstract

Scanning electron microscope (SEM) study of the pollenand seed morphology of Peganum harmala L. and Zygophyllumfabago L. (Zygophyllaceae), in native Bulgarian populations, wascarried out. Additionally, a light microscope (LM) investigation onpollen grains was made in order to elucidate the peculiarities of themajor parameters of pollen surface and size. It was established thatpollen grains in Z. fabago are pantoporate. Exine ornamentation isreticulate. 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 (incorrecttetrahedral to rhomboid), with a peaked edge, arc-curve laterally. Theseed sculpture corresponds to the Tubular to Concave-type, whichis characterized by polygonal cells and reticulate tectum. The seedsof Z. fabago are oval-rhomboid in shape. The seed sculpture correspondsto Concave to Convex-type which is characterized with polygonalcells, ranging in size, with cuticular wax folds.