Table 1.
List of the pollen samples.
Fig 1.
Measurement of Abies cephalonica pollen.
(a) FTIR spectra obtained from different sampling techniques (from top downwards): transmission IR of KBr pellet, ATR-IR of intact and ground grains, IR microspectroscopy of multigrain (mg) and single grain (sg). (b) Raman spectra obtained from two different regions of a single grain: corpus and saccus regions. The marked signals are associated with the vibrational bands of (P) proteins, (L) lipids, (C) carbohydrates and (S) sporopollenins. (c) SEM image of pollen grains in various orientations: equatorial view (up left), distal polar view (up right) and proximal polar view (down left). (d) SEM image of pollen grain in equatorial view, with saccus (up, two hemispherical substructures) and corpus regions (down, large hemispherical substructure).
Fig 2.
Spectra of representative samples of pollen measured as: (a) ATR of ground pollen, (b) Raman of corpus region, and (c) Raman of saccus region.
The spectral set consists of EMSC normalized average spectra; for better viewing the spectra are offset.
Fig 3.
carbohydrates (amylose and cellulose), protein (gluten), lipid (tristearin) and phenylpropanoids (p-coumaric, ferulic and sinapic acids); for better viewing the spectra are offset.
Fig 4.
Raman spectra of biochemicals.
carbohydrates (amylose and cellulose), protein (gluten), lipid (tristearin), phenylpropanoids (p-coumaric, ferulic and sinapic acids) and carotenoid (β-carotene); for better viewing the spectra are offset.
Fig 5.
Score plots of individual blocks and global scores of consensus principal component analysis (CPCA).
ATR-FTIR of (a) (ATI) intact pollen, (b) (ATG) ground pollen; (c) (KBR) Transmission FTIR of KBr pellets; Transmission IR microspectroscopy of (d) (MGR) multigrain and (e) (SGR) single grain; Raman spectroscopy of (f) (RMS) saccus region and (g) (RMC) corpus region of single pollen grain; (h) Global scores. Samples are labelled in accordance to pollen genus: Abies (red), Picea (green), Pinus (blue), Podocarpus (magenta), and Cedrus (cyan). The percent variances for the PCs are given in supplementary part.
Fig 6.
CPCA correlation loading plots for the first three principal components.
(a) Correlation between pollen genera (black), FTIR of KBr pellets (blue), ATR of ground pollen (red) and ATR of intact pollen (green). (b) Correlation between pollen genera (black), Raman of corpus region (red) and Raman of saccus region (green). For the sake of clarity, only the selected variables are presented. The percent variances for the first five PCs are 56.0, 12.2, 9.4, 7.5 and 5.1.