镉胁迫对茭白生长及产品残留量的影响

以茭白单季茭蒋墅茭和双季茭葑红早为试材，在土壤栽培条件下进行Cd2+浓度为25、50、100、200 mg?L-1的胁迫处理，测定了茭白生长过程中部分生理指标、形态指标及产品器官肉质茎中Cd2+残留量的变化。结果表明：分蘖前期和中期的生理生化指标及分蘖后期的形态指标，均表现为较低浓度的Cd2+胁迫促进生长、较高浓度则抑制生长；Cd2+胁迫浓度为25 mg?L-1时葑红早肉质茎中Cd2+残留量超标，但蒋墅茭在Cd2+胁迫浓度达50 mg?L-1时仍未超过无公害蔬菜产品国家标准的限量值。表明茭白对Cd2+的耐性较强，但品种间存在较大差异。

Effect of Cadmium on Growth and Residue of Zizania latifolia

Changes of some physiological and biochemical indexes and morphological indexes in leaves and roots of the Zizania latifolia were studied on single-harvested cultivar Jiangshujiao and double-harvested cultivar Fenghongzao cultured in soil with different Cd2+ concentrations.The Cd2+ concentration were 25,50,100 mg?L-1 stress.The Cd2+ residues of Zizania latifolia galls were also determined.The results showed that,some physiological and biochemical indexes in prophase and metaphase of tillering stage and some morphological indexes in anaphase of tillering stage represented that their growth were promoted when in lower concentration of Cd2+ stress and restrained when in higher concentration of Cd2+ stress.When concentration of Cd2+ stress was 25 mg?L-1,Cd2+ residues of Fenghongzao were higher than national maximum residue limit.However,the Cd2+ residues of Jiangshujiao gall were lower than national maximum residue limit of non pollutant vegetables when the concentration of Cd2+ was 50 mg?L-1.It indicates that Zizania latifolia has a high tolerance to Cd2+ stress and there exist big differences between cultivars.