镉胁迫对3种柱花草生长及植株镉积累和分配的影响

Effects of Cadmium Stress on the Growth,Cadmium Accumulation and Distribution of Three Stylosanthes spp. Varieties

利用不同浓度镉离子(Cd2+)溶液对3个柱花草(Stylosanthes spp.)品种进行不同程度的胁迫处理,以研究Cd2+胁迫对柱花草生长、镉积累及其分配的影响。结果表明:随着Cd2+浓度的增加,3种柱花草生长均受到抑制,Cd2+胁迫对西卡柱花草(Stylosanthes scabra cv.Seca)株高、分枝数、地上部和地下部生物量影响最大,其次是TPRC2001-1柱花草(Stylosanthes guianensis.TPRC2001-1),而热研2号柱花草(Stylosanthes guianensis cv.Reyan2)影响最小;在Cd2+胁迫下3种柱花草地上部和地下部Cd2+含量均显著增加,TPRC2001-1柱花草体内含Cd2+量较热研2号柱花草和西卡柱花草大;地上部富集系数随Cd2+浓度增加呈下降趋势,且在低Cd2+浓度(≤1 mg.kg-1)下更易富集Cd2+;Cd2+转运系数呈现先上升后下降。

Effects of cadmium stress on the growth,the contents of Cd2＋ and distribution of three Stylosanthes spp.varieties were investigated under treatments with different Cd2＋ concentrations.Results showed that the growth of Stylosanthes spp.was restrained with Cd2＋ concentration.Shoot height,branch number,aboveground and underground biomass of Stylosanthes scabra cv.Seca was most influenced with Stylosanthes guianensis.TPRC2001-1 and Stylosanthes guianensis cv.Reyan 2 least influenced.The Cd2＋ content in both aboveground and underground parts of three varieties significantly increased under the stress of Cd.The Cd2＋ content of Stylosanthes guianensis.TPRC2001-1 was the highest among three varieties.The Cd bioconcentration factor of the Stylosanthes spp.aboveground decreased with exogenous Cd2＋ concentration increasing.Stylosanthes spp.was more susceptible to accumulate Cd2＋ when the soil Cd2＋ concentration was lower（≤1 mg·kg-1）.Transfer coefficients were initially increased then decreased.