Study On The Tolerance Mechanism And Restoration Potential Of Leguminous Plants Rhynchosia Volubilis And Argyreia Seguinii To Cu Tailings

In this paper,two kinds of leguminous vines which were Rhynchosia volubilis and Argyreia seguinii were selected as experimental materials that were cultivated in pots.The five cultivation matrix were pure garden soil,3/4 garden soil +1/4 Cu tailings,1/2 garden soil +1/2 Cu tailings,1/4 garden soil +3/4 Cu tailings and full Cu tailings,separately.The effects of plant growth,physiological index and metal ions accumulating as well as its bioremediation capability of above two kinds of plants were studied.The other experiment were carried out in cultivation matrix of Cu tailings in which adding five different concentrations of fulvic acid(0FA,1gFA dilute 8000 times,1gFA dilute 6000 times,1gFA dilute 4000 times,1gFA dilute 2000 times),the effects of different concentrations of fulvic acid on plant growth,physiology index and Cu ion accumulation of Rhynchosia volubilis and Argyreia seguinii were studied.The main results were as follows:(1)The growth and accumulation of metal ions of Rhynchosia volubilis and Argyreia seguinii treating with different contents of Cu tailings were studied.The results shown that Rhynchosia Volubilis could be growen in Cu tailings for which lower content could be promoted the growth and development of Rhynchosia volubilis and Argyreia seguinii;Lower concentration of Cu tailings promoted the growth of Argyreia seguinii.The plants growing of Argyreia seguinii were hindered by treating with pure Cu tailings.(2)The effects of different portions of Cu tailings on the physiological indexes of Rhynchosia volubilis and Argyreia seguinii were studied,tolerance mechanism of Rhynchosia volubilis and Argyreia seguinii of heavy metal copper.The results shown that lower content of Cu tailings had slight harmful to Rhynchosia volubilis,and the defense effectivity of Rhynchosia Volubilis on Cu tailings could be promoted various physiological metabolism in plants and promoted its growth and development,and the high content of Cu tailings had less effectivity on the Rhynchosia Volubilis.Lower content of Cu tailings could be promoted the growth and development of Argyreia seguinii,plants growth of Argyreia seguinii were hindered treating by higher content of Cu tailings.(3)The effects of different concentrations of fulvic acid adding to pure Cu tailings cultivation substrate of Rhynchosia Volubilis and Argyreia seguinii were reached.The results shown that,adding 1/6FA to pure Cu tailings cultivation substrate,the endurance index of Rhynchosia Volubilis and Argyreia seguinii were the highest,for which was greater than 1.It was indicated that adding low concentration of fulvic acid to pure Cu tailings cultivation substrate reduced the enrichment ability of Rhynchosia Volubilis and Argyreia seguinii on Cu ions.The enzyme activities had no obvious change in plants,the enzyme activities of Argyreia seguinii aerial part and underground part were kept balance dynamcally to remove superoxide,improved plant growth and development status,and to clear the peroxides and improved the growth and development of plants,and the best effective was added at the concentration of 1/6FA.(4)Effects of Rhynchosia volubilis and Argyreia seguinii that growing in different Cu tailings cultivation substrates on physical and chemical properties of cultivation substrates were studied.The results shown that,the planting of Rhynchosia Volubilis and Argyreia seguinii can slightly improve the enzyme activities in the soil.The activities of phosphatase reacted strongly to the content of Cu ions.It can be used to test whether soil is damaged by heavy metal Cu,and the activities of urease in soil can be activated in the low concentration of Cu tailings.The results showed that: Rhynchosia volubilis and Argyreia seguinii could be grown in the low concentration of Cu tailings that had certain enrichment effective on heavy metal Cu,and improving soil nutrient content of Cu tailings.The resistance ability of Rhynchosia volubilis to Cu tailings was greater than Argyreia seguinii,and fulvic acid could promoted the growth of Rhynchosia volubilis and Argyreia seguinii effectively,and enhanced the tolerance of Argyreia seguinii to Cu tailings.