摘要:化学除草为作物田间管理带来方便的同时，药害问题也越来越突出，特别是苗后除草剂对作物造成的药害频繁发生。为此，本文以我国玉米主栽品种‘郑单958’、‘先玉335’、‘京科968’和‘京农科728’为试验材料，采用2，4-D丁酯和烟嘧磺隆2种苗后除草剂，每种除草剂设置0倍（人工除草，CK）、1倍（最适浓度，T1）和2倍最适浓度（T2）共3个喷施浓度处理，于玉米幼苗4展叶期喷施。研究苗后除草剂对不同基因型玉米品种生育进程、形态特征、保护酶活性和产量等性状指标的影响，旨在为玉米安全生产提供参考和指导。研究结果表明：1）喷施除草剂后，参试玉米品种的生育期呈延长趋势，‘郑单958’和‘先玉335’的生育期延长程度大于‘京科968’和‘京农科728’；2，4-D丁酯对参试品种的生育期延长幅度大于烟嘧磺隆。喷施除草剂后，参试玉米品种的叶面积、根系长度、表面积和体积呈降低趋势，且随除草剂浓度增加，降低幅度加大；品种间的反应也存在较大差异，‘郑单958’和‘先玉335’降低程度大于‘京科968’和‘京农科728’。2）喷施苗后除草剂后，参试玉米品种的叶片SOD活性、CAT活性和MDA含量在品种、除草剂和剂量间均存在极显著差异；参试玉米品种的SOD和CAT活性呈降低趋势、MDA含量呈升高趋势，且随喷施浓度增加影响加剧；不同品种间，随喷施浓度增加，‘郑单958’和‘先玉335’的SOD和CAT活性降幅高于‘京科968’和‘京农科728’；不同除草剂间，2，4-D丁酯处理的影响程度大于烟嘧磺隆。3）苗后除草剂对参试品种的穗粒数、百粒重和产量影响显著，均呈降低趋势；随除草剂浓度增加降幅增大；不同品种间，‘郑单958’和‘先玉335’的降幅大于‘京科968’和‘京农科728’。由此可见，2种苗后除草剂对参试玉米品种的生长发育和产量存在显著影响，表现在延长了生育期，抑制了根系和叶片的生长，降低了保护酶活性，并且加重了叶片的膜质过氧化程度，从而导致玉米减产显著，且随除草剂浓度增加，影响进一步加大。不同品种间，‘京科968’和‘京农科728’对苗后除草剂的耐受性好于‘郑单958’和‘先玉335’。
关键词:除草剂/
玉米品种/
生长发育/
根系/
抗氧化酶/
产量
Abstract:Chemical weed control is convenient for crop field management, but the damage has become increasingly pronounced, especially for herbicides. Field experiments were conducted to study the effects of herbicides on growth process, morphological characteristics, protective enzymes activities and yield traits of different maize varieties in this study. Four widely cultivated maize varieties in the region ('Zhengdan958', 'Xianyu335', 'Jingke968' and 'Jingnongke728') and two herbicides (2, 4-D butyl ester and nicosulfuron) were used in the experiment. No herbicide (manual weeding) was set as CK treatment, the recommended application concentration (optimum concentration) of herbicides was set as T1 treatment and two-times optimum concentration was set as T2 treatment. The herbicides were applied at V4 stage of maize. The results showed that after herbicide application, the growth period of maize varieties prolonged and those of 'Zhengdan958' and 'Xianyu335' were longer than those of 'Jingke968' and 'Jingnongke728'. The growth period of tested maize varieties after applying 2, 4-D butyl ester was longer than that after applying nicosulfuron. After spraying herbicides, leaf area, root length, root surface area and root volume of the tested maize varieties decreased, while the extent of reduction increased with increasing herbicide concentration. Leaf area, root length, root surface area and root volume of 'Zhengdan958' and 'Xianyu335' were lower than those of 'Jingke968' and 'Jingnongke728'. After spraying herbicides, SOD activity, CAT activity and MDA content were significantly different among the tested maize varieties, herbicide type and herbicide dose. SOD and CAT activities of the tested maize varieties decreased, while MDA content increased. With increasing concentration of sprayed herbicides, the effect on protective enzymes activities increased. The decrease in SOD and CAT activities of 'Zhengdan958' and 'Xianyu335' was higher than those of 'Jingke968' and 'Jingnongke728'. Also with increasing concentration, the effect of 2, 4-D butyl ester treatment was higher than that of nicosulfuron. Application of herbicides after seedling resulted in a significant reduction in grain number per ear, 100-grain weight and yield. With increasing herbicide concentration, yield reduction intensified for 'Jingke968', 'Jingnongke728', 'Zhengdan958' and 'Xianyu335', decreased respectively by 8.9%, 9.3%, 14.0% and 16.5% after using 2 times concentration of 2, 4-D butyl ester. However, it decreased by 3.6%, 5.0%, 7.9% and 8.7% after using two times concentration of nicosulfuron, respectively. The reductions in yields of 'Zhengdan958' and 'Xianyu335' were higher than of 'Jingke968' and 'Jingnongke728'. Thus the application of two herbicides after seedling had significant effects on growth period, leaf area, leaf protection enzyme activity, root characteristics, yield and yield composition of maize varieties. The inhibition effect of 2, 4-D butyl on growth and development of maize was higher than that of nicosulfuron. The extent of reduction in leaf area, protective enzyme activity, root traits and yield of the tested varieties increased with increasing application concentration. The reasons for this trend were as follows:the application of herbicides controlled weeds, but also resulted in the accumulation of peroxidation products, destruction of membrane systems, decrease in leaf area, root length, surface area and volume, and acceleration of leaf senescence in the middle and late grain-filling periods of maize. Herbicide tolerance of 'Jingke968' and 'Jingnongke728' were better than that of 'Zhengdan958' and 'Xianyu335'.
Key words:Herbicide/
Maize variety/
Growth and development/
Root/
Antioxidant enzyme/
Grain yield
?Equal contributors
注释:
1) ?同等贡献者
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