28个玉米品种子粒对重金属的吸附特性及苗期敏感性研究

为明确28个玉米品种苗期的耐重金属性和子粒对重金属的吸收特性，本研究通过测定重金属Cd、Pb、Cr、Zn、Cu单一胁迫对玉米幼苗株高等11个生理生化指标的影响，评价玉米幼苗对重金属的耐受性。通过测定不同玉米品种在四川省3个生态区的子粒重金属含量，评价子粒的重金属吸附特性。结果表明，根据苗期重金属耐受性可将28个玉米品种分为4类，其中瑞玉612和正红412为强耐重金属品种，正红818等13个品种为耐重金属品种，正红510等5个品种为中等耐重金属品种，中单808等8个品种为重金属敏感型品种。根据子粒对重金属的吸附特性可分为4类，正红205等12个品种子粒重金属含量最低，正红510等3个品种子粒重金属含量最高，瑞玉612等13个品种重金属含量处于中等水平。综合以上结果，正红818等13个品种的苗期重金属耐受性强，且子粒对重金属的吸附低，表明这些品种具有较高的推广应用安全性。

Study on Heavy Metal Absorption Characteristics and Seedling Sensitivity of 28 Maize Varieties

In order to clarify the heavy metal tolerance (HMT) of 28 maize varieties at seedling stage and the absorption characteristics of heavy metals in kernels at mature stage, this study evaluated the tolerance of seedlings to heavy metals by investigated the effects of a single heavy metal stress, such as Cd, Pb, Cr, Zn, and Cu, on 11 physiological and biochemical indexes of the maize seedling, and the heavy metal adsorption characteristics of the kernels of different maize varieties by measuring the heavy metal content(HMC) of the kernels in three ecological zones in Sichuan Province. The results showed that the tested varieties could be classified into four groupes according to the HMT at seedling stage. Ruiyu612 and ZH412 were highly tolerant to heavy metals, 13 varieties were tolerant, 5 varieties were moderately tolerant, and 8 varieties were heavy metal-sensitive varieties. The tested varieties could be divided into four classes according to the heavy metals absorption characteristics of kernels. 12 varieties had the lowest HMC in kernels, 3 varieties had the highest HMC in kernels, and 13 varieties had medium HMC in grains. Taken together, the results indicated that 13 varieties, such as Zhenghong818, had high seedling HMT and low HMC in kernels, suggesting that these varieties have a high degree of safety for popularization and application.