镉浓度对不同玉米品种幼苗生长及生理特性的影响

以玉米品种郑单958、豫单9953、正大999、京农科728为试验材料，采用实验室水培方式，设置不同Cd浓度(0、3、6、9 mg/L)，研究Cd胁迫9 d后4个玉米品种苗期生长指标及相关生理指标的差异，利用主成分分析和隶属函数法进行耐Cd性综合评价。研究结果表明，Cd对4个玉米品种苗期的株高、根长、地上部鲜重、地下部鲜重、地上部干重、地下部干重总体上起抑制作用，对根数影响较小。随着Cd胁迫浓度的升高，郑单958、豫单9953和京农科728的总叶绿素含量呈现下降的趋势，正大999呈先上升后下降的趋势。在Cd处理下，相比郑单958和正大999，京农科728和豫单9953的POD活性较对照升高更明显，且MDA含量受影响较小。根据主成分分析和隶属函数法得到4个玉米品种耐Cd能力强弱顺序为京农科728>豫单9953>郑单958>正大999。

Effects of Cadmium Concentration on Seedling Growth and Physiological Characteristics of Different Maize Varieties

Soil cadmium(Cd) pollution poses a significant threat to crop production. In this study, four maize varieties, Zhengdan958, Yudan9953, Zhengda999 and Jingnongke728 were used as experimental materials, and different Cd concentrations(0 mg/L, 3 mg/L, 6 mg/L, 9 mg/L) were set by laboratory hydroponics to study the differences of seedling growth indexes and related physiological indexes of four maize cultivars after Cd stress for 9d, and the comprehensive evaluation of Cd tolerance was carried out by principal component analysis and membership function method. The results showed that Cd had an inhibiting effect on the plant height, root length, shoot fresh weight, root fresh weight, shoot dry weigh and root dry weight at the seedling stage of the four maize varieties, but had little effect on root number. With the increase of Cd stress concentration, the total chlorophyll content of Zhengdan958, Yudan9953 and Jingnongke728 showed a downward trend, while Zhengda999 showed a trend of first rising and then decreasing. Compared with Zhengdan958 and Zhengda999, the POD activity of Jingnongke728 and Yudan9953 increased significantly compared with the control, and the MDA content was less affected. According to the principal component analysis and membership function method, the order of Cd tolerance of four maize cultivars was as follows: Jingnongke728 > Yudan9953 > Zhengdan958 > Zhengda999.