Studies On Cu Accumulation,Resistance In Four Species Of Iris L. And EDTA Accomodation

The difference of Cu accumulation and tolerance in four species of Iris. L, I. pseudacorus. I. tectorum. I. lactea var. chinesis I. halophila was studied by hydroponic method in this paper. And the tolerance of two species, I. pseudacaorus and I. lactea var. chinesis were better than others. Meantime, the effects of Cu on the physiological and biochemical parameters of I. pseudacorus, the better Cu tolerant species were researched, the effects of Cu on the contents of nutritive elements and the effects of EDTA on the Cu accumulation in I. pseudacorus and I. lactea var. chinesis were analyzed.The results were as follow: 1. The effects of Cu on the accumulation and tolerance of four species of Iris. LThe researches of effects of Cu on the biomasses and Cu contents in the shoots and roots of four species of Iris L, I. pseudacorus. I. tectorum. I. lactea var. chinesis. I. halophila, which were cultivated hydroponically in different Cu concentrations for 30 days shpwed that the lower Cu concentration (25mg/L) would promote the growth of the roots of I. pseudacorus and shoots of I. lactea var. chinesis. The Cu contents in the shoots of I, lactea var. chinesis and I. halophila were 1736.805, 1260.737μg/g respectively at 25mg/L Cu treatment, reached the standard of Cu hyperaccumulator (1000μg/g) and the shoot biomass of I. lactea var. chinesis was not significantly different with that of control. The Cu contents in the shoots of I. pseudcaorus. I. tectorum I. lactea var. chinesis I. halophila were 2805.09, 2192.75, 2419.74, 1995.20μg/g respectively at 50mg/L Cu treatment and the shoot biomasses of I. pseudacorus and I. lactea var. chinesis have no significant difference with controls. The ratios of Cu accumulations in the shoots to total Cu accumulations of I, pseudacorus. I. tectorum. I. lactea var. chinesi were raised as Cu treatment concentrations increased, while the change of the ratio of Cu accumulation in shoots to total Cu accumulations of I.halophila was ruleless. The tolerant abilities of I. pseudacorus and I. lactea var. chinesis were better than that of I, tectorum and I, halophila..The results of the changes of several physiological and biochemical parameters of four species under Cu stress shown that the contents of total chlorophyll decreased and the contents of Pro, MDA, relative electric conductivity and SOD...