Effects of DCB on the distribution of cellulose and callose in tube walls of <i>Pinus bungeana</i> Zucc.

<p>Bars = 20 µm A. Calcofluor stained control pollen tubes, showing cellulose was distributed along the whole length of pollen tube. B. Calcofluor stained DCB-treated pollen tubes, showing less cellulose was present at the pollen tube wall, especially the tube tip. C. Pollen tubes cultured in normal medium for 3 d, showing strong fluorescence, excited from callose on the whole surface of the pollen tube. D. Pollen tubes treated with DCB for 3 d, showing strong fluorescence at the pollen tube tip.