THE EFFECTS OF A TRIAZOLE FUNGICIDE, PROPICONAZOLE, ON POLLEN GERMINATION, TUBE GROWTH AND CYTOSKELETAL DISTRIBUTION IN TRADESCANTIA-VIRGINIANA

The effects of propiconazole on germination and tube growth of Tradesc antia virginiana pollen when incorporated in germination media at 0, 1 02, 136, or 170 mu l l(-1) were evaluated using light microscopy and i mmunocytochemistry. Propiconazole inhibited pollen germination, cytopl asmic streaming, and tube elongation. Treatments also induced abnormal tube morphology and cytoskeletal distribution. Tubes treated with pro piconazole displayed weaker microfilament (Mf) signals along the polle n tubes, with amorphous staining. Microtubule (Mt) distribution was al so severely affected. In treated tubes, the proximal portions had char acteristically fragmented Mts. Fewer Mt bundles were seen in the subap ical region, and these were located further from the apex. Propiconazo le effects were generally concentration dependent. The results indicat e that propiconazole affects both Mfs and Mts; however, the effects ma y be an indirect result of the drug's influence on membranes.