华南地区不同品系水稻积累砷特征及其影响因素

选用华南地区较为常见的杂交稻、优质常规稻2个水稻品系,16个水稻品种,通过土壤盆栽试验,待其成熟收获后,分析水稻根表、根部、秸秆、糙米中砷含量及相关影响元素的含量,旨在研究不同水稻品系（种）对砷吸收、转运和积累规律以及其影响因素,为低积累、高耐性水稻品系（品种）的选择及相应的农业措施提供科学的理论依据。结果表明,砷在水稻中的分布情况为根表〉根部〉秸秆〉糙米;供试的糙米中砷含量为0.18~0.47mg.kg-1,均符合国家卫生标准（GB4810—1994）。水稻根表铁锰膜中砷含量随根表中铁、锰的增加而富集,相关分析表明,根表铁锰膜形成可以有效降低糙米砷积累,而秸秆磷可以有效降低秸秆中砷的积累。杂交稻各部位的砷含量及转移系数均高于常规稻,且秸秆和糙米砷含量差异达到显著水平;天优122的糙米砷积累能力高于其他品种,美香占2号低于其他品种。

Characteristics of Arsenic Accumulation in Different Rice（Oryza sativa L.） Cultivars and Its Influencing Factors in South China

Sixteen conventional and hybrid rice（Oryza sativa L.） cultivars,which are widely planted in South China,were used in a soil pot experiment to study arsenic absorption,transfer and accumulation and its influencing factors.The results showed that arsenic concentrations in rice tissue decreased in the order of root surfacerootstrawgrain.Arsenic content in rice grain,ranged from 0.18 to 0.47 mg·kg-1,met national hygienic standard（GB 4810—1994）;Arsenic content in iron and manganese plaques on root surface increased with the increase of root surface Fe and Mn contents,indicating that the formation of iron and manganese plaques could reduce grain arsenic accumulation;in addition,phosphorus levels could effectively reduce arsenic accumulation in straw.Arsenic content and transfer coefficient in different parts of hybrid rice were higher than those of conventional rice,with arsenic content in straw and grain reaching significant difference.Grain arsenic accumulation in Tianyou 122 was higher than other cultivars,whereas Meixiangzhan 2 was lower than others.The results suggested that arsenic concentration in rice grain could be decreased by means of screening rice cultivars with low arsenic accumulation and increasing P concentration in rice straw.