Effects of Zinc and Cadmium Stresses on the Germination Characteristics of Four Weed Species Seeds

PurposeIn order to investigate the effects of heavy metal zinc and cadmium pollution on weed seed germination indicators in farmland soil.

MethodUsing 4 species of seeds as test materials, the difference between a series of germination indicators of weeds (Buglossoides arvense, Silence conoidea , Cirisum setosum and Descurainia sophia) were compared under the single stress of zinc (Zn²⁺) and cadmium (Cd²⁺). The subordinate function method was used to comprehensively evaluate the tolerance of 4 species of farmland weeds under Zn and Cd stress.

ResultWith the increase of Zn²⁺ and Cd²⁺ mass concentration, the germination indicators of the 4 species of weed seeds decreased to different degrees, except for S. conoidea, which showed a certain fluctuations in its germination rate, germination potential and germination index when the Zn²⁺ mass concentration of 50-400 mg/L and Cd²⁺ mass concentration of 25-200 mg/L. According to the comprehensive membership function analysis, the tolerance of 4 species of weeds under the Zn stress was S. conoidea>C. cd setosum>D. sophia>B. arvense, the tolerance of 4 species of weeds under the stress was C. setosum>S. conoidea>D. sophia>B. arvense.

ConclusionThe S. conoidea had the strongest tolerance to heavy metal zinc, C. setosum had the strongest tolerance to heavy metal cadmium. However, B. arvense had the weakest tolerance to both zinc and cadmium.