重金属污染对稻米品质影响的研究

Studies on the Influences of Heavy Metal Pollution on the Qualities of Brown Rice.

土壤受重金属污染后,能影响稻米营养和卫生品质。镉能显著降低糙米赖氨酸含量,以及赖氨酸和组氨酸占总量的百分数,提高天冬氨酸的含量;铅降低缬氨酸占总量的百分数,提高苯丙氨酸含量。铅、镉污染还影响糙米淀粉的组成,提高糙米中还原糖的含量。糙米的铅、镉含量与土壤污染程度显著相关,杂交晚稻籽粒对铅、镉的富集能力比早稻强。

Crop yield is usually used as a main index to evaluate the degree of heavy metal pollution of farming soil. Little is known about the effect of heavy metals on the nutritive qualities of brown rice. Pot experiments were conducted in 1989 to determine the effects of Pb, Cd, and Zn on the con- tents of amino acids, amylum, reductive sugar and heavy metals in brown rice. The results showed that the content of lysine and the rates of lysine and histidine to the total amino acids of brown rice reduced and the celtents of aspartic acid and so on increased significantly with the additional Cd content to the soil. The rate of valine reduced and the content of phenyl alanine and the rates of phenyl alanine and aspartic acid increased significantly with the addition of the soil Pb content. There was a significantly positive corelation between the contents of amylopectin of brown rice and Cd of the soil. The content of amylose was negatively corelated to Pb content of the soil significantly. Along with the increase of the contents of Pb and Cd or Pb, Cd and Zn added to the soil, the content of reductive sugar of brown rice increased significantly. There was a significantly positive corelation between the contents of the metals in the brown rice and that in the soil. Hybrid rice had a stronger ability than ordinary rice in taking up the heavy metals.