Effects of Neodymium on Growth, Pectinase Activity and Mycelium Permeability of Fusarium oxysporum

Abstract

The diameter of the colony of Fusarium oxysporum in solid medium, and the mycelium growth, pectinase activity, and mycelium permeability of Fusarium oxysporum in liquid medium under varying concentrations of Nd 3+(0, 2, 4, 10, 20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 300, and 400 mg·L −1) were measured. The results indicated that the growth of Fusarium oxysporum was stimulated in solid medium when the concentration of Nd 3+ ranges from 2 to 180 mg·L −1, whereas it was inhibited when Nd 3+ concentration was greater than 200 mg·L −1. The colonies were fewer and smaller when Nd 3+ was used in the solid medium. The growth of Fusarium oxysporum was inhibited in liquid medium when Nd 3+ was used. The inhibition rate showed by the dry weight of mycelium ranged from 4.83% to 52.18% and increased with Nd 3+ concentration. The pectinase activity decreased compared with that of controls. When the concentration of Nd 3+ was 10 and 400 mg·L −1, the pectinase activity decreased by 95% at both concentrations. Mycelium cell membrane permeability increased when Nd 3+ concentrations ranged from 10 to 400 mg·L −1 but decreased when Nd 3+ concentration was 2 mg·L −1.