Study On Tolerance Of Five Species Of Garden Flower To Copper Stress

The thesis was based on the characteristics of uptake, accumulation, transformation, rehabilitation of copper contaminated on five garden flower species including Orychophragmus violaceus (L.) O.E.Schulz, Euphorbia splendens Des Moulins, Tagetes erecta.Linn., Begonia semperflorens Link et Otto and Helianthus tuberosus.Linn., as well as influence of Cu stress on growth, physiological and biochemical activities. One sensitive plant and two indicator species for Cu contamination were screened. The research results provided reference and basis for vegetation restoration and construction in Cu contamination area. The major research results were as follows:(1) The growth of all threated plants were influenced with the different Cu treat level. In a case of low Cu concentration, five garden flower species were in healthy growth status; as the enriched Cu concentration in the solution, some of the threated plants grew weak, or dead.(2) Under high Cu concentration treatment, comparing with control plants, the biomass of Helianthus tuberosus.Linn., Orychophragmus violaceus (L.) O.E.Schulz, Begonia semperflorens Link et Otto and Tagetes erecta.Linn. had dropped off 38.76%,30.47%,12.17% and 12.10% separately; but the biomass of Euphorbia splendens Des Moulins had climbed up 28.41%. According the variation with the biomass of five species, the growth of Helianthus tuberosus.Linn. and Orychophragmus violaceus (L.) O.E.Schulz were seriously inhibited, Begonia semperflorens Link et Otto and Tagetes erecta.Linn. were at the middle, Euphorbia splendens Des Moulins was better than control plants.(3) The main parts where five plants accumulated Cu were different. The other four flowers accumulated Cu into their roots, while Orychophragmus violaceus (L.) O.E.Schulz into its aerial part. In five species, the overground part of Begonia semperflorens Link et Otto had the largest Cu content of 623.62mg·kg-1; and the underground part of Tagetes erecta.Linn. had the largest Cu content of 454.43mg-kg-1.(4) In high concentration treatment of Cu, the Cu accumulation of different species followed these sequences:Orychophragmus violaceus (L.) O.E.Schulz (1.58mg)> Helianthus tuberosus.Linn. (0.74mg)> Tagetes erecta.Linn. (0.37mg)> Euphorbia splendens Des Moulins (0.19mg)> Begonia semperflorens Link et Otto (0.15mg)(5) The ability of migration and transformation of different species followed these sequences: Orychophragmus violaceus (L.) O.E.Schulz> Euphorbia splendens Des Moulins> Begonia semperflorens Link et Otto> Helianthus tuberosus.Linn.> Tagetes erecta.Linn.(6) With the increasing Cu concentration, the content of chlorophyll of five garden flower species reduced, but chlorophyll a/b increased.The POD activity of five garden flower species increased with the increasing Cu concentration; and the activities of SOD and CAT increased first but then decreased. Therefore, according to the analysis about the physiological activities of five species, the research drew a conclusion that the growth of Orychophragmus violaceus (L.) O.E.Schulz and Helianthus tuberosus.Linn. were seriously inhibited, Euphorbia splendens Des Moulins was less affected, and Tagetes erecta.Linn. and Begonia semperflorens Link et Otto were at the middle.The results indicated Tagetes erecta.Linn. and Begonia semperflorens Link et Otto had a wider tolerance to Cu contamination, and they could be used as heavy-metal-tolerant plant. At the same time, Orychophragmus violaceus (L.) O.E.Schulz could be selected as Cu contamination indicator plant.Since the special ability of self-adjustment, Euphorbia splendens Des Moulins had application in phytostabilization.