Influence of potassium in the agar medium on the growth pattern of the filamentous fungus Fusarium solani

Abstract

A decrease in the concentration of K+ ions below 3 mM in agar medium which also contained starch, casein hydrolysate, MgSO4, and K2HPO4 changed the growth pattern of Fusarium solani illuminated in diurnal 12-h light/12-h dark cycles from zonation to a feathery growth mode. Rubidium or cesium ions could replace potassium, but lithium, sodium, and the bivalent alkaline earth ions could not.