Phenopalynological Study of Some Ornamental Species in the Giza Region, Egypt

Mature flower buds were collected from twenty species planted on the different roads in the Giza district from May to September 2022 and 2023. The pollen grains were examined carefully and photographed using a 40x10x magnification lens in an OPTICA (B-150D) light microscope fitted with a USB digital video Camera and Computer Software. At least 30 pollen grains/each species were measured and described. Non-catalyzed pollens were sputtered onto Aluminum stubs, coated with 30 nm gold, and examined and photographed using JEOL JSL IT 200 SEM. The morphological characters of the pollen grains were examined. According to the pollen size Acalypha wilkesiana and Tecoma stans were the smallest pollen grains, from 20.0μm to 26.0μm, which facilitate their introduction to the nose causing asthma and rhinitis. Clerodendrum inerme pollen grains have echinate exine surface, which causes allergic symptoms more than the psilate ones. Plumbago capensis has intectate exine with echinate columella causing human disorders. This study demonstrates the critical position of air pollution in this area with the change in the phenological aspects of the plants resulting in producing immature pollen grains in huge amounts, which cause human disorders and pollinosis. Our results showed that the studied species can induce allergy in one way or another if we consider the situation of the studied area, weather pattern, and pollen characteristics.