叶面喷施硅硒联合水分管理对水稻镉吸收转运特征的影响

为研究水稻叶面喷施硅硒溶液联合稻田不同水分管理对中轻度镉污染农田水稻镉吸收转运特征的影响,在田间设置4种叶面喷施处理和2种水分管理交互的裂区试验,共8个处理:稻田常规水分管理下,叶面喷施去离子水(W1CK)、硅溶胶(W1Si)、亚硒酸钠溶液(W1Se)、硅硒等体积混合液(W1SS);孕穗后期稻田持续淹水管理下,叶面喷施去离子水(W2CK)、硅溶胶(W2Si)、亚硒酸钠溶液(W2Se)、硅硒等体积混合液(W2SS)。结果表明,叶面喷施硅硒溶液处理和孕穗后期淹水处理对水稻生长和产量性状均没有显著影响。常规水分管理下,与对照W1CK处理相比,W1Si和W1Se处理分别降低水稻糙米中镉含量的71.7%和61.9%(P0.01),同时镉从水稻根到茎的转运系数分别降低27.4%和34.5%,从茎到叶的转运系数分别增加46.5%和55.3%。孕穗后期持续淹水管理下,W2CK处理与W1CK处理相比糙米镉含量降低57.5%(P0.05),而叶面喷施硅硒溶液处理组与W2CK相比,糙米中镉的含量没有显著差异(P0.05)。水稻叶面喷施硅硒溶液和孕穗后期稻田持续淹水,可以有效阻止镉在水稻体内的迁移,显著降低水稻糙米对镉的积累。叶面喷施硅硒联合稻田孕穗后期淹水管理对水稻糙米降镉效果未见协同效应。

Effect of silica and selenite foliar sprays on the uptake and transport of cadmium by rice under water management

The aim of the present study was to investigate the combined effect of foliar applications and water management on the uptake and transport of cadmium by rice. Field experiments were conducted to test the interactive effects of four foliar treatments and two water treatments, foliar treatments included deionized water(W1CK), a silica solution(W1Si), a sodium selenite solution(W1Se), and a 1:1 mixture of the silicon and selenium solutions(W1SS), two water treatments included conventional water management and continuous flooding during the late booting stage. Neither foliar spraying nor flooding had a significant effect on the growth or yield of brown rice. However, under conventional water management, the W1Si and W1Se treatments reduced the cadmium content of the brown rice by 71.7% and 61.9%(P<0.01), respectively, when compared to the control treatment(W1CK), and the root-to-stem transfer coefficient decreased by 27.4% and 34.5%, respectively, whereas the stem-to-leaf transfer coefficient increased by 46.5% and 55.3%, respectively. Under continuous flooding during the late booting stage, the W2CK treatment reduced the cadmium content of the brown rice by 57.5%(P<0.01), when compared to W1CK treatment, whereas the W2Si, W2Se, and W2SS treatments had no significant effect(P>0.05). Even though the foliar Si and Se sprays and continuous flooding during the booting stage could both be used to prevent the migration of cadmium in rice plants and to reduce the accumulation of cadmium in brown rice, the combination of foliar treatment and water management failed to exhibit a synergistic effect on the cadmium content of brown rice.