不同生育期脱水对稻米镉含量的影响

为进一步探究水分管理对稻米镉含量的影响，以6 个早稻品种、4 个晚稻品种为研究材料，通过盆栽试验研究了不同生育期脱水（分蘖期脱水，T1；孕穗期脱水，T2；抽穗期脱水，T3；乳熟期脱水，T4；蜡熟期脱水，T5；全生育期淹水，CK）对稻米镉含量的影响。结果表明：脱水处理、品种及二者交互效应对稻米镉含量的影响均达到极显著水平(P＜0.01)，不同处理间精米镉含量的大小顺序为T3＞T1＞T2＞T4＞T5＞CK，W2（‘C两优7 号’）、W12（‘湘晚籼13 号’）、W8（‘金优59’）3 个品种的耐镉特性及稳定性较好，适合一般污染区大面积种植。精米镉含量在水稻品种类型之间存在极显著差异(P＜0.01)，其含量由高到低为超级杂交稻、常规稻、杂交稻；生育类型不存在主效应。

Effects of Drought Stress in Different Growth Stages on Grain Cadmium Content of Rice

To explore the effect of water management on cadmium (Cd) content in rice, a pot experiment with 6 early-rice cultivars and 4 late-rice cultivars was conducted to study the effects of drought stress on grain Cd content in rice under different growth stage, including soil drying at tillering stage (T1), soil drying at booting stage (T2), soil drying at heading stage (T3), soil drying at milk stage (T4), soil drying at dough stage (T5), and whole growth season flooding (CK). The results showed that: the main effects of cultivar and water management as well as their interactive effects on Cd content in polished rice were significant (P<0.01); the Cd content in polished rice followed the sequence of T3>T1>T2>T4>T5>CK; W2 (‘C-liangyou 7’), W12 (‘Xiangwanxian 13’), W8 (‘Jinyou 59’) with low and stable Cd content in grain, can be widely planted in slight pollution soil. Significant (P<0.01) difference was observed in polished rice Cd content among cultivar types. Super hybrid rice had the highest Cd content, followed by conventional rice and hybrid rice. Growth duration had no significant effect on Cd content in polished rice.