Studies On Seeding Growth And Physiological And Biochemical Indexes Of Chlorophytum Comosum Under The Stress Of Pb²⁺ And Cd²⁺

ABSTRACT: This paper studied the growth and physiological effects of Chlorophytum comosum under different concentration of single Pb, Cd and Cd-Pb compounds by the methods of soil culture and water culture, investigated how Chlorophytum comosum bear the pollution of Pb and Cd and the interaction between Pb and Cd, which offered some evidence on alleviating the damage caused by Pb and Cd .The main conclusions are as follows:1.With soil culture experiment, low concentration of Pb²⁺ (≤1000mg·kg^-1) and Cd²⁺ (0.3 mg·kg^-1) can promot the growth of Chlorophytum comosum slightly. Total biomass,Overground biomass ,Plant height, Number of leaf and Length of leaf increased with the control ,and the difference was significant.With the increasing concentration of single Pb²⁺,Cd²⁺ and Pb²⁺-Cd²⁺ compounds ,the growth of Chlorophytum comosum has been inhibited severely.Single Pb²⁺ and Cd²⁺ and Pb²⁺-Cd²⁺compounds has not great effects on the underground biomass,Leaf width and length of root.The poisoning effect of Pb²⁺-Cd²⁺ on the growth of Chlorophytum comosum was stronger than single Pb²⁺ and Cd²⁺ stress.The concentration of Pb²⁺and Cd²⁺ would inhibite the growth of Chlorophytum comosum when cultivated via water culture,while promoted its growth when cultivated via soil culture,so we could conclude soil amortized the damage of Pb²⁺and Cd²⁺ . The interactive effect of Cd²⁺ and Pb²⁺ was antagonistic and synergistic. 2.With water culture experiment, under concentration of Pb²⁺ (≤800 mg·L^-1) and Cd²⁺ (0.3 mg·L^-1), the growth of Chlorophytum comosum was promoted slightly.Total biomass ,Overground biomass ,Plant height, Number of leaf and Length of leaf increased with the control .With the increasing concentration of single Pb²⁺,Cd²⁺ and Pb²⁺-Cd²⁺ compounds ,the growth of Chlorophytum comosum has been inhibited.Same as soil culture experiment, Pb²⁺ and Cd²⁺ and Pb²⁺-Cd²⁺compounds has not great effects on the underground biomass,leaf width ,but has great effects on length of root.The effect of Pb²⁺-Cd²⁺ compound on the growth of Chlorophytum comosum was stronger than single Pb²⁺and Cd²⁺ stress. The interactive effect of Cd²⁺ and Pb²⁺ was antagonistic and synergistic.But no matter cultivated in soil or in water, the interactive effect of Cd²⁺ and Pb²⁺ was complicated,not simply additive,antagonistic and synergistic ,but also related with many factors.3.No matter cultivated in soil or in water,under single Pb²⁺,Cd²⁺ and Pb²⁺-Cd²⁺ compounds treatment, the contents of chlorophyll rised and then declind. When cultivated in soil, under concentration of Pb²⁺ (300mg·kg^-1) and Cd²⁺ (5 mg·kg^-1),the contents of chlorophyll increased slifhtly. But cultivated in water , under concentration of Pb²⁺ (100 mg·L-1) and Cd²⁺ (0.3mg·L-1),the contents of chlorophyll increased .With the increasing concentration of single Pb²⁺,Cd²⁺ and Pb²⁺-Cd²⁺ compounds ,the chlorophyll concent was gradually declined . Pb²⁺-Cd²⁺ compounds had stronger effect on chlorophyll content.MDA gradually increased with the increasing concentration of Pb²⁺,Cd²⁺ and Pb²⁺-Cd²⁺ compounds,and had positive correlation with Pb²⁺and Cd²⁺ concentration.