DIFFERENTIAL MECHANISMS OF MOVEMENT BETWEEN A GENERATIVE CELL AND A VEGETATIVE NUCLEUS IN POLLEN TUBES OF NICOTIANA-TABACUM AS REVEALED BY ADDITIONS OF COLCHICINE AND NONANOIC ACID

The growth of pollen tubes of Nicotiana tabacum cultured in a petri di sh was divided into five stages by the behaviors of pollen tubes, vege tative nuclei (VNs), and generative cells (GCs). Pollen tubes continue d to elongate during every stage. Colchicine, at a concentration of 1 mM, preferentially inhibited the movement of the VNs but not that of G Cs. Nonanoic acid preferentially inhibited the movement of GCs. These results suggest that different mechanisms of movement exist between VN s and GCs.