A HISTOLOGICAL AND ELEMENTAL ANALYSIS STUDY OF THE MATURE SEED OF BEGONIA-SEMPERFLORENS

The total element content and the subcellular distribution of mineral nutrients were investigated in a species that has very minute seeds. The major storage substances in the seed of Begonia semperflorens were lipids sequestered in lipid vesicles and proteins concentrated in protein bodies. Transmission electron microscopy revealed the presence of protein crystalloids and electron-dense globoid crystals in the protein bodies. These inclusions varied both in size and number in protein bodies from different tissues. Energy dispersive X-ray analysis of the globoid crystals showed the high Mg, K, and P levels characteristically found in phytin from large-sized seeds. Small traces of Ca were found in globoid crystals within protein bodies found in the provascular tissue of the embryo. Neutron activation analysis was used to measure the elemental composition of the whole seed and these results were correlated with the findings of energy dispersive X-ray analysis studies of globoid crystals.