Wang Aiyun, Wang Minyan, Liao Qi, He Xiquan
College of Forestry, Central South University of Forestry and Technology, Changsha, 410004, China.
School of Metallurgy and Environment, Central South University, Changsha, 410083, China.
Environ Sci Pollut Res Int. 2016 Mar;23(6):5410-9. doi: 10.1007/s11356-015-5781-z. Epub 2015 Nov 13.
Maize (Zea mays) has low Cd accumulation in grains and a high biomass compared to other crops. The capacities for Cd accumulation in different maize cultivars are, however, not fully understood. To reduce human health risk from maize grown in Cd-contaminated soil and to provide promising maize cultivars for the phytoremediation of Cd-polluted soil, a field experiment was conducted to screen low-Cd- and high-Cd-accumulation maize cultivars by evaluating the yield, Cd uptake, translocation, and accumulation differences among 19 maize cultivars. There were differences in straw dry weight (DW), root DW, and yield among the 19 cultivars. The cultivars Yudan19, Zhengda999, and Xianyu508 had a higher production compared to that of the other cultivars. The Cd concentrations in the roots were much higher than those in the straws and grains in all cultivars. The Cd accumulation factors (AFS) decreased in the order of accumulation factors in root (AFrs) > accumulation factors in straw (AFss) > accumulation factors in grain (AFgs). The Cd translocation factors (TFs) from root to straw (TFrs) were significantly (p < 0.05) larger than those from straw to grain (TFsg) among all of the cultivars. The TFs for all of the cultivars was less than 1, and the lowest TFsg (0.23) was found in cultivar Xiangyongdan3. The correlation analysis indicated that Cd concentrations in straws showed a significant (p < 0.01) as well as positive correlation with TFrs while a negative correlation with TFsg (p < 0.01). Moreover, Cd accumulation in different tissues decreased in the order straw > grain > root. Among the 19 maize cultivars, Jixiang2118 and Kangnong18 accumulated the highest Cd amount in the aboveground tissues, and the corresponding values were 7,206.51 and 6,598.68 mg hm(-2), respectively. A hierarchical cluster analysis based on the Cd concentrations in grains and straws classified the 19 maize cultivars into four and two groups for a 0.4 minimum distance between clusters, respectively. Yudan19, Zhengda999, and Xianyu508 can be classified into one group in which low Cd in grains meeting the Cd tolerance limit in foods set by China National Standard, suggesting that those cultivars are safety for food and human health. However, Jixiang2118 and Kangnong18 can be classified as another group with potential application for phytoremediation in slightly or moderately Cd-polluted soil because of the high Cd accumulation in the aboveground tissues.
与其他作物相比，玉米（Zea mays）籽粒中镉积累量低且生物量高。然而，不同玉米品种的镉积累能力尚未完全明确。为降低镉污染土壤种植玉米带来的人体健康风险，并为镉污染土壤的植物修复提供有前景的玉米品种，开展了一项田间试验，通过评估19个玉米品种的产量、镉吸收、转运和积累差异，筛选低镉和高镉积累的玉米品种。19个品种间秸秆干重、根干重和产量存在差异。与其他品种相比，品种豫单19、正大999和先玉508产量更高。所有品种根中的镉浓度均远高于秸秆和籽粒中的镉浓度。镉积累系数（AFS）按根中积累系数（AFrs）＞秸秆中积累系数（AFss）＞籽粒中积累系数（AFgs）的顺序降低。所有品种从根到秸秆的镉转运系数（TFs）（TFrs）显著（p＜0.05）大于从秸秆到籽粒的转运系数（TFsg）。所有品种的TFs均小于1，品种湘甬单3的TFsg最低（0.23）。相关性分析表明，秸秆中的镉浓度与TFrs呈显著（p＜0.01）正相关，与TFsg呈负相关（p＜0.01）。此外，不同组织中的镉积累量按秸秆＞籽粒＞根的顺序降低。在19个玉米品种中，吉祥2118和康农18地上部组织中镉积累量最高，相应值分别为7206.51和6598.68 mg hm(-2)。基于籽粒和秸秆中镉浓度的层次聚类分析分别将19个玉米品种分为4组和2组，聚类间最小距离为0.4。豫单19、正大999和先玉508可分为一组，其籽粒中镉含量低，符合中国国家标准规定的食品镉耐受限量，表明这些品种对食品和人体健康安全。然而，吉祥2118和康农18可归为另一组，因其地上部组织中镉积累量高，在轻度或中度镉污染土壤植物修复中有潜在应用价值。
