Intraspecific variations in cadmium tolerance and phytoaccumulation in giant duckweed (Spirodela polyrhiza).

•There exists a great intraspecific variation in Cd phytoaccumulation and biological response to Cd in giant duckweed.•Growth maintenance under Cd exposure is the most critical mechanism contributing to Cd accumulation ability.•Low dose of Cd has little effect on starch content in giant duckweed.