Differential responses of poplar cultivars to cadmium stress at seedling stage
[Objective]By simulating Cd stress,the differences in Cd stress among different poplar cultivars were explored,and cultivars with strong tolerance to heavy metal Cd were selected to provide theoretical basis for poplar remediation of heavy metal contaminated soil.[Method]A pot experiment was conducted on 6 poplar cultivars using the method of simulating Cd stress,and 10 indicators including growth,biomass of different organs and Cd2+content were measured.The comprehensive index was calculated using the membership value and weight of each indicator to evaluate the ability of different cultivars to resist Cd stress.[Result]The seedling height and ground diameter showed a decreasing trend with the increase of Cd2+ concentration,the seedling height trait was more sensitive than ground diameter to Cd stress.By comparing the mean root biomass of different cultivars,it was found that Populas×liaoningensis,P.×euramericana'Zhongliao1'and P.×euramericana'Bofeng1'ranked in the top three.The stem biomass,leaf biomass and total biomass of different cultivars showed a trend of first increasing and then decreasing with the increase of Cd2+ concentration.Analysis showed that the stem biomass of P.×euramericana'Zhongliao1',P.cathayana×canadensis'Xinlin1'and P.×euramericana'Bofeng1'ranked in the top three,while the leaf biomass of P.×euramericana'Zhongliao1',P.×liaoningensis and P.×euramericana'Bofeng1'were in the top three,and the total biomass of P.×euramericana'Zhongliao1',P.×liaoningensis and P.cathayana×canadensis'Xinlin1'ranked in the top three.The Cd2+ content in the roots,stems,leaves and total Cd2+ content of each cultivar increased with the increase of Cd2+ concentration.At the highest Cd2+ treatment concentration,the Cd2+ content in the roots and stems of P.deltoides×(P.nigra var.thevestina×P.nigra),P.×euramericana'Bofeng1'and P.cathayana×canadensis'Xinlin1'ranked among the top three in terms of growth rate compared to the control;The growth rate of Cd2+ content in leaves of P.deltoides×(P.nigra var.thevestina×P.nigra),P.cathayana×canadensis'Xinlin1'and P.×euramericana'Zhongliao1'ranks in the top three compared to the control;The total Cd2+ content of P.deltoides×(P.nigra var.thevestina×P.nigra),P.cathayana×canadensis'Xinlin1'and P.×euramericana'Bofeng1'ranks among the top three with a growth rate compared to the control.[Conclusion]According to the size of the comprehensive index,the order of resistance to Cd stress is P.×euramericana'Zhongliao1',P.×liaoningensis,P.×euramericana'Bofeng1',P.cathayana×canadensis'Xinlin 1',P.deltoides×(P.nigra var.thevestina×P.nigra)and P.alba×P.berolinensis.P.×euramericana'Zhongliao1',P.×liaoningensis,P.×euramericana'Bofeng1'and P.cathayana×canadensis'Xinlin 1'show good resistance to Cd stress,with P.×euramericana'Zhongliao1'reaching 0.955 2,so they can be used to repair heavy metal cadmium contaminated soil in their suitable areas.
万方数据
维普
