土壤镉含量影响水稻产量与稻穗镉累积分配的品种间差异

Varietal Difference in Yield and Cd Accumulation and Distribution in Panicle of Rice Affected by Soil Cd Content

以谷粒镉(Cd)积累能力不同的3个晚稻品种(天优华占、星2号和湘晚籼13号)为材料,在人为设置的3个土壤Cd含量条件下,研究土壤镉含量提高对水稻产量与稻穗镉累积分配特性的影响及其品种间差异。结果表明:(1)土壤Cd含量提高使水稻产量下降,在添加1.0mg/kg Cd时各品种均显著减产,以天优华占降幅最大;土壤Cd含量提高对水稻产量构成因素的影响具有品种间差异,但其使各品种产量下降的主要原因基本一致,即主要由有效颖花数、结实率与收获指数下降导致。(2)稻穗与谷粒各部分Cd含量均随土壤Cd含量提高而显著提高,但并不呈直线增长趋势,3个品种的提高幅度表现天优华占>星2号>湘晚籼13号趋势。(3)稻穗Cd累积量随土壤Cd含量提高而显著提高,品种间稻穗Cd累积量呈天优华占>星2号>湘晚籼13号趋势。(4)稻穗Cd主要累积在实粒中,但实粒Cd所占比例随土壤Cd含量提高呈下降趋势,3个品种实粒Cd所占比例呈星2号>天优华占>湘晚籼13号趋势。可见,土壤Cd含量提高对水稻产量与稻穗Cd累积分配的影响具有明显的品种间差异,Cd污染程度不同的稻田应因地制宜选择水稻品种。

Three late rice varieties with different grain Cd accumulation ability, Tianyouhuazhan, Xing No.2 and Xiangwanxian No. 13, were used as materials to study the effect of increasing soil Cd content on rice yield and Cd accumulation and distribution in rice panicle and its varietal difference under different soil Cd content conditions. The results showed that： （1） Increasing soil Cd induced yield decrease, and yield of all varieties decreased significantly by adding 1.0mg/kg Cd, and the decreasing extent of Tianyouhuazhan was the biggest. Effects of increasing soil Cd on rice yield components had varietal difference, while the main reasons for yield decreasing was almost the same, that was mainly by decreasing effective kernels, seed setting rate and harvest index. （2） Cd content in rice panicle and grain was significantly increased with the increment of soil Cd content, while it existed no linear correlation, and the increasing extent showed the trend of Tianyouhuazhan 〉 Xing No.2 〉 Xiangwanxian No. 13. （3） Cd accumulation in rice panicle was significantly increased with the increment of soil Cd content, showing the trend of Tianyouhuazhan〉 Xing No.2 〉Xiangwanxian No. 13. （4） Cd in rice panicle was mainly accumulated in filled grains, while the proportion of Cd in filled grains to Cd in whole panicle was decreased with the increment of soil Cd content, and the proportion of Cd in filled grains to Cd in whole panicle showed the trend of Xing No.2 〉 Tianyouhuazhan〉Xiangwanxian No. 13. The results showed that the effects of increasing soil Cd content on yield and accumulation and distribution of Cd in rice panicle existed clear varietal difference, and the different rice variety should be selected in paddy filed with difference Cd content.