不同生育期Cd胁迫对水稻生长及镉累积的影响

Effects of cadmium stress on growth and cadmium accumulation in rice at different growth stages

采用水培试验方法,从水稻移栽至某特定生育期之间添加外源镉(Cd),通过递推减法,研究了湘晚籼13号水稻不同生育期Cd胁迫对其生长和不同部位中Cd含量的影响.结果表明,50μg·L^(-1)外源Cd胁迫不会影响水稻的正常生长发育,糙米中的Cd主要来源于水稻分蘖期吸收的Cd在后期的迁移、灌浆期吸收的Cd和成熟期吸收的Cd,这3个关键生育期对糙米中最终Cd含量的贡献率分别为36.4%、18.2%和16.4%.因此,与灌浆期和成熟期相比,在水稻分蘖期采用一些植物阻隔技术可能对水稻籽粒中Cd含量的削减更为重要.

Effect of Cd stress on growth and accumulation of Cd in different parts of rice Xiangwanxian No.13 at its different growth periods were investigated by hydroponic experiment with addition of exogenous Cd and recursive subtraction method.The results showed that the growth of rice was not significantly affected by addition of 50 μg·L-1 exogenous Cd.Cd in brown rice was mainly derived from migrating of absorbed Cd in the later stage of tillering period,uptake of Cd at the grain filling period,and Cd absorption during maturity period,accounting for 36.4%,18.2% and 16.4% of the total Cd accumulation in the brown rice,respectively.The use of some plant barrier techniques may be more important for reduction of Cd content in rice grains at the tillering period than the grain filling and maturity periods.