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

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.