Pollen diversity among the inconstant male Ochradenusbaccatus delile populations in Egypt

Abstract

In Egypt, Resedaceae is represented by 14 species belonging to five genera, genus Ochradenus is among them represented by one species (O. baccatus Delile). The studied Ochradenus baccatus populations collected from Wadi Degla, Egypt revealed that O. baccatus is gynodioecious species, with female individuals that are constant in sex expression and males that exhibit great variation in functional gender. The field study revealed the presence of inconstant male of O. baccatus in different forms ranging from high fruit-producing to low or nonfruit producing forms with two intermediate forms. The pollen morphology of all the four forms was examined using LM and SEM. This study is the first dealing with pollen grain morphological diversity within different O. baccatus populations, representing model of the inconstant male of a gynodioecious species. Generally, the examined Ochradenus baccatus pollen grains appeared under SEM as 3-colporate, isopolar, radiallysymmetrical, with reticulate exine sculpturing. This study revealed the presence of a variability in pollen size, shape, aperture and exine sculpturing in different forms. The polymorphic pattern observed in inconstant O. baccatus male populations in Egypt was attributed to internal factors, the polyploidy phenomenon was among them and the external factors were excluded.