EFFECT OF COLCHICINE ON SPERMATOGENESIS IN A FERN, PTERIDIUM-AQUILINUM (L) KUHN

Treatment of developing antheridia of Pteridium aquilinum for 24 h with radioactive and normal colchicine resulted in spermatocytes with restitution nuclei, binucleate spermatocytes with multiple immature blepharoplasts, and spermatids in which the organization of the microtubular ribbon and basal bodies, and the shaping of the nucleus were seriously disturbed. The results indicate that the coiling of the multilayered structure and the condensation of the chromatin, two key events in spermatogenesis, are independent of tubulin polymerization.Transitional stages were observed between the granular material of the blepharoplast and microtubules. Colchicine affected the assembly of the cartwheel structure of the basal bodies less than that of the triplets, which were often rudimentary or absent. Autoradiographs were only partially successful because of the failure to devise a satisfactory method of embedding by freeze-substitution, but there was clear evidence of colchicine binding by nuclei in young spermatocytes. © 1979, Annals of Botany Company.