Staining Pollen Tubes in the Style; Cotton Blue versus Carmine for General Use

Abstract

Pollen tubes passing through the style are fixed in acetic-alcohol (1 : 1) at 60 C for 30 min; softened by boiling in water 5–30 min; cleared in lactic acid at 60 C, 30 min; stained in lactophenol-cotton blue (1%) at 60 C, 15–30 min; and mounted in lactic acid. This procedure was found to be more generally applicable to angiosperms than carmine, applied in propionic-lactic acid mixtures. It has been tested on 36 species, including 4 monocotyledons and 32 dicotyledons.