CALCIUM IN ELECTRON-DENSE GLOBOIDS DURING POLLEN GRAIN MATURATION IN CHLOROPHYTUM-ELATUM RBR

The localization, elemental composition and quantitative changes in in soluble, electron-dense globoids observed in the course of pollen grai n development in Chlorophytum elatum R.Br. have been investigated. Dur ing pollen maturation, small electron-dense globoids were only found w ithin larger electron-light vesicles in the cytoplasm of the vegetativ e cell. The number and diameter of the electron-dense globoids increas ed during pollen grain maturation, and decreased after pollen germinat ion. By energy-dispersive X-ray microanalysis, the presence of calcium , magnesium and phosphorus was detected in these globoids. The results are discussed in the light of previous findings with regard to phytat e metabolism and the role of calcium in pollen germination.