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选用籽粒着粒密度差异较大的密穗型品种秀水63和散穗型品种秀水11,种植于受重金属轻度污染的土壤,研究了晚粳稻籽粒中有毒重金属As、Cd、Cr、Ni、Pb含量的品种与粒位效应。结果表明,重金属含量的粒位间差异秀水63明显大于秀水11,As、Cd、Cr、Pb含量粒位间差异显著,Ni含量差异较小。穗上部籽粒As、Cd、Ni含量高于中部籽粒,穗下部籽粒最低,而Cr、Pb则正好相反。稻米中几种重金属含量与粒重的关系因重金属种类不同存在着差异,籽粒As、Cd、Ni含量与粒重呈正相关,而Cr和Pb含量与粒重呈负相关。秀水63和秀水11不同粒位的籽粒灌浆模式存在差异,下位粒灌浆速率较低,使粒重较上、中位粒低,导致粒重有较大的粒位差异,而这种差异也与穗部着粒密度有关,秀水63明显大于秀水11。籽粒As、Cd、Ni含量与最大灌浆速率(GRm)呈正相关,与到达最大灌浆速率时间(Tpoi)呈负相关,而Cr和Pb含量与以上两个籽粒灌浆特性参数分别呈负相关和正相关,说明籽粒As、Cd、Ni的积累与碳水化合物的积累具有相同或相近的模式,而Cr和Pb表现为不同的积累模式。
Seedlings of Xiushui 63, a spike-type cultivar with large difference in grain densities, and Xiashui 11, a panicle-type cultivar, were planted in soils heavily contaminated with heavy metals. The effects of As, Cd, Cr, Ni, Pb Content Varieties and Grain Position Effects. The results showed that the intersubspecific difference of heavy metal content, Xiushui 63, was significantly larger than that of Xiushui 11, and there were significant differences among the grain positions of As, Cd, Cr and Pb, while the difference of Ni contents was small. The contents of As, Cd and Ni in the upper panicle were higher than those in the middle panicle, while the grains in the lower panicle were the lowest while that of Cr and Pb were the opposite. The relationship between the contents of heavy metals and grain weight in rice is different due to different heavy metal species. The contents of As, Cd and Ni in grain are positively correlated with the grain weight, while the contents of Cr and Pb in grain are negatively correlated with grain weight. There was a difference in the grain filling pattern between Xiushui 63 and Xiushui 11 at different grain positions. The lower grain filling rate was lower, which resulted in lower grain weight than the upper and middle grains, which led to a larger grain size difference Spike grain density related, Xiushui 63 significantly larger than Xiushui 11. The contents of As, Cd and Ni in grains were positively correlated with the maximum filling rate (GRm) and negatively correlated with the maximum filling rate (Tpoi), while the contents of Cr and Pb were negatively correlated with the above two grain filling parameters, The results showed that the accumulation of As, Cd and Ni in grains had the same or similar patterns with the accumulation of carbohydrates, while Cr and Pb showed different patterns of accumulation.