Effect of Ca2+, Mg2+, light, temperature and pH on athelial stage formation in Sclerotium rolfsii Sacc.

The role of the divalent cations, Ca 2+ and Mg 2+ as well as light, temperature and pH in the induction of sexual reproduction of Sclerotium rolfsii in potato dextrose agar medium supplemented with Cyperus rotundus rhizome powder was investigated. EDTA (ethylenediaminetetraacetic acid) at 15 mmol/l suppressed hymenium induction without affecting growth or sclerotium formation. This effect was reverted by the addition of divalent cations. Chlorpromazin, a calmodulin antagonist, and ruthenium red, an organelle Ca 2+ channel blocker, did not have any effect on the induction process. Continuous white light inhibited the sexual stage formation while blue, green and red light did not. Maximum percent area covered in the Petri dish by basidial stage was produced under complete darkness at a range of pH 4-8.