镉胁迫下硅对不同品种水稻镉积累的影响

Effect of Silicon on Different Rice Varieties under Cadmium Stress

为明确施硅条件下不同品种水稻对镉的响应,在中和硅酸钠碱性和消除钠离子影响的基础上,通过盆栽试验研究镉胁迫下硅对两个品种水稻镉积累的影响。结果表明:水稻对镉毒害的响应存在明显的基因型差异,与对照相比,镉胁迫下“辽星19”和“辽粳9”的生物量和产量均极显著降低(p<0.01),生物量分别降低20.79%和24.94%,产量分别降低21.50%和34.31%;水稻糙米中镉含量极显著增加(p<0.01),分别是各自对照处理的46.94倍和35.27倍;“辽星19”镉的转移系数和富集系数也都高于“辽粳9”。镉胁迫下,施硅显著提高水稻的生物量和产量,降低糙米镉的含量和镉的转移系数与富集系数;其中“辽星19”生物量增加8.75%~10.00%、“辽粳9”增加4.40%~20.06%,“辽星19”和“辽粳9”稻米的转移系数分别降低30.17%~57.76%和45.25%~72.07%;富集系数分别降低24.63%~58.77%和40.11%~63.81%;当施硅量(以SiO2计)大于100mg·kg^-1土时,“辽粳9”糙米中镉含量已能符合国家食品污染物限量标准安全要求。施硅不能改变不同品种水稻对镉胁迫响应的差异,但可在一定程度上抑制水稻对隔的积累;选用镉低积累品种,施用适量硅的情况下,可实现镉污染稻田水稻的安全生产。

In order to clarify the responses of different rice varieties under Cd stress,based on neutralizing sodium silicate alkalinity and eliminating the effect of sodium ions,the effects of silicon on cadmium accumulation in two rice varieties under cadmium stress were conducted by pot experiments.The results showed that there was a significant genotype difference in the response of rice to cadmium toxicity.Compared with the control,under the stress of cadmium toxicity,the biomass was significantly decreased by 20.79%and 24.94%,and the yield was significantly decreased by 21.50%and 34.31%for“Liaoxing 19”and“Liaogeng 9”,respectively.The content of cadmium in brown rice increased significantly(p<0.01),which was 46.94 times and 35.27 times that of the control treatments respectively.The transfer coefficient and enrichment coefficient of cadmium in“Liaoxing 19”were higher than those in“Liaogeng 9”under cadmium stress.The application of silicon significantly increased the biomass and yield of rice,and decreased the cadmium content,cadmium transfer coefficient and enrichment coefficient of brown rice,the biomass was increased by 8.75%-10.00%for“Liaoxing 19”,and by 8.75%-10.00%for“Liaogeng 9”,respectively.The transfer coefficient of brown rice decreased by 30.17%-57.76%and 45.25%-72.07%for“Liaoxing 19”and“Liaogeng 9”,respectively.The enrichment coefficient of brown rice decreased by 24.63%-58.77%and 40.11%-63.81%for“Liaoxing 19”and“Liaogeng 9”,respectively.When the amount of silicon applied(calculated as SiO2)was greater than 100 mg·kg^-1 soil,the cadmium content in“Liaogeng 9”brown rice has reached the standard of the National Food Pollutant Limit.Silicon application could not change the response of different rice varieties to cadmium stress,but it could inhibit the accumulation of cadmium in rice to some extent.The safe production of rice in cadmium-contaminated paddy fields can be realized by selecting varieties with low accumulation of cadmium and applying an appropriate amount of silicon.