SIMS investigation of the distribution of K(+), Na(+), Mg(2+) and Ca(2+) cations in birch pollen

betula betula verrucosa calcio calcium cation cationes cations citoplasma cytoplasm cytoplasme elektronenmikroskopie endoplasmic reticulum magnesio magnesium methode methods microscopia microscopie microscopy mitochondria mitochondrie mitocondria polen pollen potasio potassium sodio sodium