Distribution, Accumulation and Translocation of the Heavy Metal Cd in Various Varieties of Edible Rapeseed under Cd Stress

Abstract

To examine the safety of producing edible rapeseed in heavy-metal-contaminated farmland, field experiments were performed with 25 varieties of edible rapeseed on farmland lightly polluted with Cd in the central southern part of Hunan Province. Growing characteristics and Cd contents in rapeseed tissues were measured, and Cd uptake, translocation and removal potential were calculated. The results showed that the growth of 25 rapeseed varieties was not inhibited without withering or inconsistent changes in the shoot. The shoot and root Cd contents of rapeseed varieties ranged from 0.05 to 0.26 mg·kg−1 and 0.04 to 0.26 mg·kg−1, respectively. The bioaccumulation factor (BCF) showed that the shoot had a greater capacity for Cd transport than roots. The total Cd removed by rapeseed varieties ranged from 1.606 to 16.159 μg·plant−1. There were significant differences in plant height, BCF of soil available Cd in the shoot, translocation factor (TCF) of Cd from root to shoot and Cd intake by rapeseed among the edible rapeseed varieties. Cluster analysis of Cd accumulation in the 25 rapeseed varieties indicated that Lvjin 1, Guanyou Qingjing and Guanyou brassica not only reduced soil pollution but also allowed for the production of safe leafy rapeseed, although Cd contents in the shoot of 25 rapeseed varieties did not exceed the national safety standards of China.