Stress of Simulated Acid Rain on Root Properties of Morus alba var. Nongsang 14 in Cadmium Contaminated Soil

In the spring 2019, cuttings of Morus alba var. Nongsang 14 were potted in Cadmium contaminated soil in Lin’an, Zhejiang province. 60 days of recovering later, experiment of two factors (simulated acid rain, cadmium contaminated soil) with 3 levels were conducted on seedlings. By the end of September, determinations were implemented on seedling height, ground diameter, root system indicators. The results showed that root phenotype and biomass accumulation of M. alba var. Nongsang 14 seedlings decreased under 25 mg/kg of Cd, but the growth of aboveground part did not change significantly. Under treatment of 50 mg/kg of Cd, these tested indicators were significantly lower than that of the control (0 mg/kg of Cd & pH7.0). Treatments with pH 4.5 had no significant effect on these indicators, but that with pH 3.0 significantly reduced, as well as Mg and Fe contents in roots. The interaction between treatment of AR and Cd was significant. Compared to those under low concentration of Cd without AR (pH 7.0) treatment, plant height, root phenotype, root activity and root Mg and Fe contents under low concentration Cd with AR (pH4.5) treatment were significantly lower, and root Cd content was significantly higher.