【摘要】 为探明喷施锰肥对叶用油菜累积镉的调控作用,采用盆栽试验,研究喷施不同浓度的MnSO₄、Mn（CH₃COO）₂和EDTA·Na₂Mn对两种叶用油菜（Cd低积累品种华骏和普通品种寒绿）生物量以及Cd和Mn含量的影响,并通过分析Cd在叶用油菜体内的吸收转运规律以及亚细胞分布特征揭示其作用机理。结果表明,喷施3种形态Mn肥对Cd低积累叶用油菜地上部和根部生物量无显著影响,喷施高浓度Mn（CH₃COO）₂和EDTA·Na₂Mn显著降低普通叶用油菜地上部生物量。喷施MnSO₄和Mn（CH₃COO）₂处理降低叶用油菜Cd含量、提高Mn含量的效果明显优于EDTA·Na₂Mn处理,其中,0.4 g·L^-1Mn的MnSO₄和0.2 g·L^-1Mn的Mn（CH₃COO）₂处理降低Cd低积累叶用油菜地上部Cd含量的效果最佳,可使其分别降低29.2%和31.0%。喷施Mn肥显著降低叶用油菜总Cd累积量,使Cd转运系数显著升高,叶用油菜地上部Cd含量与总Cd累积量呈极显著的相关性（P<0.01）,而与Cd转运系数则无显著相关性。Cd和Mn在叶用油菜地上部主要分布在细胞可溶组分中,其次为细胞壁。喷施Mn肥后,Cd和Mn在细胞壁组分的分配比例降低,在可溶组分的分配比例升高。总之,喷施0.4 g·L^-1Mn的MnSO₄和0.2 g·L^-1Mn的Mn（CH₃COO）₂可以显著降低低积累叶用油菜地上部Cd含量,提高其Mn含量,同时不影响叶用油菜生长,是保障Cd低积累叶用油菜安全优质生产的较好措施。更多还原

【Abstract】 In order to test the effect of foliar application of manganese（Mn）fertilizers on cadmium（Cd）accumulation in pak choi（Brassica chinensis）, three different forms of Mn, MnSO₄, Mn（CH₃COO）₂ and EDTA·Na₂Mn, were sprayed among two pak choi cultivars（Huajun and Hanlv）in a pot experiment. We examined the biomass, Cd and Mn concentrations, Cd uptake and transport, and Cd and Mn subcellular distribution in pak choi. The results show that foliar application of Mn had no significant effect on the shoot and root biomasses of the low Cd-accumulating cultivar（Huajun）; however, the foliar application of high dosages of Mn（CH₃COO）₂ and EDTA·Na₂Mn significantly reduced shoot biomass in the common cultivar of pak choi（Hanlv）. Foliar application with MnSO₄ and Mn（CH₃COO）₂ resulted in greater alleviation of shoot Cd concentrations and a more notable enhancement of shoot Mn concentrations in pak choi than by spraying with EDTA·Na₂Mn. Shoot Cd concentrations in Huajun were the lowest under foliar feeding with 0.4 g·L^-1 Mn（MnSO₄）and 0.2 g·L^-1 Mn [Mn（CH₃COO）₂],which were decreased by 29.2% and 31.0%, respectively. Foliar Mn application reduced the total Cd accumulation significantly and increased the Cd transfer factor of pak choi markedly. The shoot Cd concentration of pak choi was positively correlated（P<0.01）with total Cd accumulation; however, it was not significantly correlated with the Cd transfer factor. In shoots of pak choi, the majority of Cd and Mn were associated with the soluble fraction, followed by the cell wall fraction. After foliar Mn application, the proportions of Cd and Mn in the cell wall fraction decreased and those in the soluble fraction increased. In summary, foliar feeding with 0.4 g·L^-1 Mn（MnSO₄）and 0.2 g·L^-1 Mn [Mn（CH₃COO）₂] significantly reduced Cd concentrations and increased Mn concentrations in shoots, and it did not affect the growth of Huajun, which is suitable for the safe and high-quality production of pak choi.更多还原