Histochemical localization of non-sulphated and sulphated polysaccharides of the red alga Hypnea musciformis

Specific chemical staining was used for the localization of polysaccharides in plant sections. Light microscope studies using toluidine blue staining reactions indicate that the most highly sulphated polysaccharides are probably K-carrageenan, the most highly sulphated compounds are found in the extra-cellular matrix and also in the intercellular regions of the sub-cortical and medullary cells. Tetraspores and carpospores had no methacromasia. The PAS reaction for polysaccharides is negative for the different regions of the cell wall. PAS reaction results in an intense staining of the carpospores and tetraspores, indicating the presence of the floridean starch grains.