Staining and Observing Pollen Tubes in the Style by Means of Fluorescence

TLDR

Pollen tubes in tomato and other flowering plant styles can be visualized using a fluorescence technique. Styles are fixed in formalin‑acetic‑80% alcohol, cleared with 8 N NaOH, stained with 0.1 % aniline blue in 0.1 N K₃PO₄, and examined under 356 nm UV illumination in a darkened room. Under these conditions callose fluoresces bright yellow‑green, sharply contrasting with bluish or grayish stylar tissue, and pollen tubes are delineated by a callose lining and irregularly spaced callose plugs.

Abstract

AbstractPollen tubes in the styles of the tomato and of other flowering plants can be observed by using the following technic. Styles are fixed in formalin-acetic-80% alcohol (1:1:8) and cleared and softened in a strong (8 N) sodium hydroxide solution. Staining is accomplished in a 0.1% solution of water-soluble aniline blue dye dissolved in 0.1 N, K3PO4. The styles are smeared or are observed whole under a conventional or dissecting microscope by direct illumination with ultraviolet light of a wavelength of about 356 m°. Observations are made in a darkened room. Under these conditions callose fluoresces bright yellow-green and contrasts strongly with the bluish or grayish fluorescence of the stylar tissue. The pollen tubes are outlined by a callose lining and irregularly spaced callose plugs.