苗期水稻吸收和转运砷的基因型差异研究

采用营养液培养的方法,研究了在根表无铁氧化物膜形成的情况下,苗期水稻对生长介质中三价砷和五价砷吸收及向地上部转运的基因型差异。水稻植株分别暴露在含20(M五价砷和含五价砷、三价砷各10(M的营养介质中14d,对水稻生物量的影响存在显著的基因型差异,在6个水稻基因型中,砷处理促进了根系的生长,但抑制了地上部的正常生长,只有基因型94D-22除外,2周的砷暴露对其生长虽然有抑制作用,但这种抑制效应并不显著;不同程度的砷暴露并没有对根中砷浓度、地上部砷浓度产生明显影响(94D-22除外),但基因型之间砷浓度的变化趋势与有铁膜形成时相比存在明显差异。营养液中三价砷和五价砷共存时,基因型94D-22茎叶中砷浓度最高(69.5mg/kg),是其他基因型的1.8～3.1倍,并且94D-22对砷的吸收能力和转移能力也最大,KY1360和94D-64对砷的转移能力最弱,这与有铁膜形成且经过整个生长季的水稻对砷吸收和转运能力的影响结果不同。

Study of Genotypic Differences on Arsenic Uptake by and Translocation in Rice Seedlings

A hydroponic experiment was conducted to investigate arsenic uptake by and translocation in rice seedlings among six genotypes. Arsenic exposure enhanced the growth of rice root and inhibited shoot growth of different genotypes, except for 94D-22. There was no significant difference in arsenic concentrations in roots and shoots between control plants and rice plants exposed to nutrient solutions with arsenate or with arsenite-arsenate respectively. However, there were significant differences in arsenic levels in roots and shoots among six genotypes. Arsenic exposure did not affect Specific Arsenic Uptake (SAU) by rice root. In addition, SAU and translocation factor were the highest for genotype 94D-22, which was different from the situation with iron plaque formed on the rice root surface.