Physiological Response of Four Widely Cultivated Sunflower Cultivars to Cadmium Stress

Abstract

Selection of sunflower varieties with greater cadmium (Cd) tolerance and detecting physiological variation under different Cd concentrations are important to study the potential of sunflower (Helianthus annuus L.) in the phytoremediation of Cd. The aim of this study was to investigate the variation in the Cd tolerance among four sunflower varieties (79−79, 363, 8361, ADT). Photosynthesis was determined using a Li−6400 XT portable photosynthesis system. Inductively coupled plasma mass spectrometry was used to detect the accumulation of Cd in different plant parts (leaf, stem and root). Subsequently, the Cd amount per plant, bio−concentration factor (BCF), and translocation factor (TF) were calculated. Cd exposure caused a decline in photosynthesis in four sunflower varieties. The 79−79 species displayed the highest Cd concentrations in tissues and 363 displayed a higher BCF in aerial parts under Cd exposure among the four species. Under Cd stress, the total soluble sugars in roots remained unaffected in 363. Based on the results of this experiment, the cultivar of 79−79 and 363 were more tolerant to Cd when compared to the other sunflower cultivars ADT and 8361. The present investigation results indicate that 79−79 and 363 can be further applied in the field trials of phytoremediation practices in contaminated soil.