The impact of soil cadmium contamination on growth and cadmium accumulation in the seedlings of different pumpkin hybrid varieties

Abstract

【Objective】 Soil contamination by cadmium (Cd) is a problem for agriculture production in many countries. One remediation method is to improve the tolerance of crops to Cd. In this paper, we investigate the tolerance of the seedlings of different pumpkin varieties to Cd contamination and Cd accumulation in the plants. 【Method】 The experiment compared seven pumpkin varieties: 360-3×041-1, Yanbian-4×Lingchuanc1, Yanbian-3×360-3, Yanbian-2×041-1, Hetou a2×360-3, Yanbian-3×Lingchuan c1, and Hetou a2×041-1. They were all grown in pots repacked with soils contaminated by Cd at concentration of 0, 8 and 16 mg/L, respectively. During the experiment, we measured the growth, physiological traits of the plants, as well as Cd accumulation in the plants. 【Result】 ① Compared to the control without Cd contamination, Cd stress significantly reduced plant height, dry and fresh mass of the Yanbian-3×Lingchuan c1 and Hetou a2×041-1 varieties, but had no significant impact on the 360-3×041-1 variety. ② Regardless of Cd stress levels, the 360-3×041-1 had the highest activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), and the lowest electrical conductivity. ③ The Cd content in the above-ground part of 360-3×041-1 and Yanbian-4×Lingchuan c1 was significantly lower than that in other varieties; their associated Cd transfer coefficient was small and the Cd accumulation was low. ④ Comprehensive analysis showed that in soil contaminated by Cd at concentration of 8 mg/L, the tolerance of the seven varieties to Cd was ranked in the order of 360-3×041-1>Yanbian-4×Lingchuanc1>Yanbian-3×360-3>Yanbian-2×041-1>Hetou a2×360-3>Yanbian-3×Lingchuan c1>Hetou a2×041-1. In soil contaminated by Cd at concentration of 16 mg/L, their tolerance to Cd was ranked in the order of 360-3×041-1>Yanbian-4×Lingchuan c1>Yanbian-3×360-3>Hetou a2×360-3>Yanbian-3×Lingchuan c1>Yanbian-2×041-1>Hetou a2×041-1. 【Conclusion】 Comprehensive analysis shows that the varieties 360-3×041-1, Yanbian-4×Lingchuan c1 and Yanbian-3×360-3 were more tolerant to Cd stress, especially 360-3×041-1 which had the lowest cadmium transfer coefficient and can healthily grow in Cd contaminated soils.

Keywords

• cadmium stress
• growth physiology
• transfer coefficient
• membership function