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