Effect of Chelating Agents and Metal Ions on Growth and Fertility in the Male Clones of the MossMicrodus brasiliensis(Dub.) Ther

Abstract

The male gametophores of Microdus brasiliensis become fertile after 48 d on basal medium. EDDHA increases gametophore number and percentage of fertile gametophores at lower concentrations (10-8-10-6 mol dm-3), whereas EDTA enhances both the responses at all levels (10-8-10-4 mol dm-3). Their iron salts increase gametophore number as well as the number of fertile gametophores, and the latter effect is more striking. The number of antheridia per head also increases with Fe-EDTA, and at higher concentrations antheridia are induced 4 d earlier. EDTA and Fe-EDTA-stimulated antheridial formation is associated with a corresponding increase in endogenous iron. Copper content increases only at higher levels of EDTA and Fe-EDTA, and there is no correlation with the antheridial induction response. Salicylic acid increases the number of gametophores and the percentage of fertile gametophores only at lower concentrations (10-8-10-6 mol dm-3), and ferric citrate does so at all levels. With salicylic acid, antheridia are induced 3 d earlier. The number of gametophores as well as the percentage of fertile gametophores increases with the increase in copper sulphate concentration. Co-addition of EDTA (10-5 mol dm-3) and copper sulphate inhibits both the responses at higher levels. Among the chelating agents tried, Fe-EDTA is most effective in enhancing antheridial production.