Effects of cadmium on the growth and physiological characteristics of sorghum plants

Abstract

The effects of cadmium (Cd) stress on the growth and physiological characteristics were studied in 3 sorghum species viz., sweet sorghum [Sorghum bicolor (L.) Moench. cv. Hunnigreen], sorghum hybrid sudangrass (Sorghum bicolor × Sorghum sudanense, cv. Everlush) and sudangrass [Sorghum sudanense (Piper) Stapf cv. Xinjiang]. The results show that low concentration of Cd²⁺ improved the growth of sorghum plants, but high concentrations of Cd²⁺ (50 mg kg⁻¹ and 100 mg kg⁻¹) significantly depressed the growth of sorghum plants; Cd stress on chlorophyll synthesis positively correlated with the Cd²⁺ concentration; root activities negatively correlated with the concentration of Cd²⁺ at each growth stage; the malondialdehyde (MDA) contents increased under low concentration of Cd²⁺ (≤ 25 mg kg⁻¹) treatment, but significantly decreased when the concentration of Cd²⁺ was more than 50 mg kg⁻¹.

Key words: Cadmium, sorghum plants, physiological characteristics.