Additions of different accumulator straws affect the growth and cadmium uptake of Ziziphus acidojujuba seedlings

Abstract

ABSTRACT This study examined the effects of straw from cadmium (Cd)-accumulator plant species on the growth and Cd uptake of Ziziphus acidojujuba seedlings grown in Cd-containing soil. The treatments were independent applications of straw from seven Cd-accumulator plant species (Cardamine hirsuta, Gnaphalium polycaulon, Pterocypsela laciniata, Malachium aquaticum, Galium aparine, Conyza canadensis, and Stellaria media) and a no-straw control. The whole-plant biomass, total chlorophyll and soluble sugar contents, and antioxidant enzymes activities in Z. acidojujuba seedlings under the different straw treatments showed the following trend: P. laciniata > M. aquaticum > S. media > C. canadensis > G. polycaulon > control > G. aparine > C. hirsuta. Compared with the control, the Cd contents in roots of Z. acidojujuba seedlings after any straw application significantly decreased by 19.05%-43.76%, and the Cd contents in shoots decreased by 31.58%-54.39%, except after G. aparine, G. polycaulon, and C. hirsuta straws applications. Therefore, the application of P. laciniata, M. aquaticum, and S. media straws promoted the growth and reduced the Cd uptake of Z. acidojujuba seedlings most significantly, making them ideal remediation materials for Cd-contaminated jujuba orchards.