Present study was conducted to investigate the Cadmium (Cd) phytoextraction potential of two plants (Veronica anagallis-aquatic and Epilobium laxum Royle) for Cd removal from induced saline water. In hydroponic system...Present study was conducted to investigate the Cadmium (Cd) phytoextraction potential of two plants (Veronica anagallis-aquatic and Epilobium laxum Royle) for Cd removal from induced saline water. In hydroponic system, various concentrations of the Cd (50, 100, and 150 ppm) and NaCl salt (1000, 3000, and 6000 ppm) were used alone and in various combinations to evaluate the effect of salt (NaCl) concentrations on Cd absorption and accumulation in Veronica anagallis and Epilobium plants. The Cd at higher concentrations (100 and 150 ppm) significantly reduced the growth and biomass of both plants and addition of salt (NaCl) to growth media (Hoagland solution) further reduced the growth. The Cadmium (Cd) translocation factor (TF) of Epilobium plant was more than one (1), while the Veronica plant showed translocation factor less than 0.5. Veronica plant showed higher Bio-concentration factor (BCF) as more than 3.5 and Epilobium plant demonstrated Bio-concentration factor less than 1 (BCF 1 is a threshold limit for a plant to be hyper-accumulator of Cd). Conclusively, the Veronica anagallis plant is reported as Cd hyper-accumulator, while Epilobium laxum plant as non hyper-accumulator on the basis of BCF values in the present findings. Further study on Veronica and Epilobium plants is recommended.展开更多
Aims Fire has important consequences on vegetation dynamics.In fire-prone areas,natural selection favors plant species,characterized by a large soil seed bank,and that their germination is stimu-lated by fire.Although...Aims Fire has important consequences on vegetation dynamics.In fire-prone areas,natural selection favors plant species,characterized by a large soil seed bank,and that their germination is stimu-lated by fire.Although seed germination stimulated by fire heat is common in the eastern Mediterranean Basin,only little is known about germination stimulation by smoke.We examined the inter-active effect of aerosol smoke and fire history on the germina-ble soil seed bank(GSSB)community in eastern Mediterranean woodlands.Methods We collected soil samples from sites that have been subjected to different fire frequencies during the last four decades and exposed them to aerosol smoke,with or without watering.By document-ing the seed germination patterns characterizing these samples,we could test for changes in the abundance and richness of the germi-nable seeds in the soil.Important Findings Total GSSB density was higher in sites that were burned more fre-quently during the last four decades.Exposure to aerosol smoke increased the GSSB density,and this pattern was more pronounced in samples originating from sites burned more frequently,as well as among annual species.Notably,exposing wet samples to aerosol smoke caused a significant reduction in GSSB density and richness.These results highlight the importance of exploring germination responses using intact soil samples,rather than synthetic seed com-munities.Moreover,our findings emphasize the important role smoke plays in shaping post-fire succession processes in the Mediterranean Basin,mainly by stimulating the germination of annual species.展开更多
文摘Present study was conducted to investigate the Cadmium (Cd) phytoextraction potential of two plants (Veronica anagallis-aquatic and Epilobium laxum Royle) for Cd removal from induced saline water. In hydroponic system, various concentrations of the Cd (50, 100, and 150 ppm) and NaCl salt (1000, 3000, and 6000 ppm) were used alone and in various combinations to evaluate the effect of salt (NaCl) concentrations on Cd absorption and accumulation in Veronica anagallis and Epilobium plants. The Cd at higher concentrations (100 and 150 ppm) significantly reduced the growth and biomass of both plants and addition of salt (NaCl) to growth media (Hoagland solution) further reduced the growth. The Cadmium (Cd) translocation factor (TF) of Epilobium plant was more than one (1), while the Veronica plant showed translocation factor less than 0.5. Veronica plant showed higher Bio-concentration factor (BCF) as more than 3.5 and Epilobium plant demonstrated Bio-concentration factor less than 1 (BCF 1 is a threshold limit for a plant to be hyper-accumulator of Cd). Conclusively, the Veronica anagallis plant is reported as Cd hyper-accumulator, while Epilobium laxum plant as non hyper-accumulator on the basis of BCF values in the present findings. Further study on Veronica and Epilobium plants is recommended.
基金This research was co-supported by the United States-Israel Binational Science Foundation(BSF Grant 2012081).
文摘Aims Fire has important consequences on vegetation dynamics.In fire-prone areas,natural selection favors plant species,characterized by a large soil seed bank,and that their germination is stimu-lated by fire.Although seed germination stimulated by fire heat is common in the eastern Mediterranean Basin,only little is known about germination stimulation by smoke.We examined the inter-active effect of aerosol smoke and fire history on the germina-ble soil seed bank(GSSB)community in eastern Mediterranean woodlands.Methods We collected soil samples from sites that have been subjected to different fire frequencies during the last four decades and exposed them to aerosol smoke,with or without watering.By document-ing the seed germination patterns characterizing these samples,we could test for changes in the abundance and richness of the germi-nable seeds in the soil.Important Findings Total GSSB density was higher in sites that were burned more fre-quently during the last four decades.Exposure to aerosol smoke increased the GSSB density,and this pattern was more pronounced in samples originating from sites burned more frequently,as well as among annual species.Notably,exposing wet samples to aerosol smoke caused a significant reduction in GSSB density and richness.These results highlight the importance of exploring germination responses using intact soil samples,rather than synthetic seed com-munities.Moreover,our findings emphasize the important role smoke plays in shaping post-fire succession processes in the Mediterranean Basin,mainly by stimulating the germination of annual species.
