Identification of pollen grains of some species of Eugenia and Syzygium (Myrtaceae) using Fourier transform infrared spectroscopy

Abstract

Four plant species have been collected from the parks and botanic gardens in Egypt; namely: Eugenia supraxillaris, Eugenia uniflora, Syzygium cumini, Syzigium jambos. These species were tentatively selected from the two genera Eugenia and Syzygium for studying their pollen morphology. Farther, their pollens have been undertaken as modules representing preliminary trials to test the efficiency of the Fourier transform infrared (FT-IR) spectroscopy as a tool for pollen grains identification. This methodology is applied as a novel tool to screen the chemical compositions of pollen grains. In case of successful application of this method, a larger number of Myrtle taxa can be subject to future studies for unraveling the knots of controversy and taxonomic arguments about the stability or segregation of some species of the two genera mentioned above. Pollen samples, belonging to the four species under investigation, were examined with light photomicroscope as regards to some morphological features, principally: pollen shape; size; aperture characters; and pollen class. The results obtained showed that the pollens of the examined species were oblatespheroidal toprolate spheroidal in shape. Tricolporate and tetracolporate types were detected in all the studied taxa. FT- IR identification revealed that all the studied species were closely similar with regard to their chemical compositions. Thus, the results obtained at this stage might assume that the pollen grains of the Eugenia and Syzygium species under investigation exhibit close similarity.