Histochemistry of Pollen Tube Growth in vivo in Triticum durum Desf

Abstract

The histochemical constitution of pollen, pollen tubes and pistillar tissues of Triticum durum Desf. before, during and after pollination was studied in vivo. The polysaccharides, RNA, proteins, lipids and reducing sugars were determined. At all phases of development, stigmatic branches have very low concentrations of polysaccharides, reducing sugars and rich RNA and nuclear proteins. Lipids increase during pollination and decrease later during pollen tube growth. The germinating pollen grains have high concentrations of polysaccharides, RNA, proteins and lipids. However, these are decreased when the pollen tubes have grown to a considerable length. The pollen tubes in stigma and style contain high concentrations of polysaccharides, lipids, RNA and proteins, but reducing sugars were absent. It is inferred that these macromolecular substances play an essential role in bringing about the growth of pollen tube in the stigma and style in vivo.