3个玉米品种苗期耐寒性鉴定

为鉴定不同玉米品种的耐寒性,筛选抗寒性强的品种,以玉米品种青农8号、郑单958和农大108为材料,在10、4℃下进行苗期低温胁迫试验,研究低温处理对超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性以及丙二醛(MDA)和可溶性蛋白(SP)含量等耐寒性鉴定指标的影响。结果表明,SOD活性及其变化率、CAT活性变化率、POD活性及其变化率、MDA含量变化率和SP含量等7个指标的结果均表明青农8号耐寒性最强;CAT活性、MDA含量和SP含量变化率等3个指标的结果表明青农8号耐寒性居第2位。农大108和郑单958耐寒性强弱在不同生理指标下得到的结论不尽相同,SOD活性及其变化率、POD活性及其变化率、MDA含量和SP含量等6个指标的结果表明农大108耐寒性优于郑单958;CAT活性及其变化率、MDA含量变化率和SP含量变化率等指标的结果表明郑单958耐寒性优于农大108。本研究结果为玉米新品种青农8号的推广以及抗寒性品种的选育提供了一定的理论依据。

Identification of the Cold Tolerance of Three Maize Varieties in the Seedling Stage

To identify cold tolerance of different maize varieties,Qingnong No.8,Zhengdan 958 and Nongdal08 were selected treated at the temperature of 4℃ and 10℃ in the seedling stage.The activities of superoxide dismutase (SOD),catalase (CAT),peroxidase (POD),and contents of malonadehyde (MDA) and soluble protein (SP) were detected.The results presented here showed that Qingnong No.8 was the best in cold tolerance from seven indexes including the SOD activity,POD activity,MDA content and the change rate of SOD activity,POD activity,SP content,CAT activity.However,other three indexes including CAT activity,MDA content and the change rate of SP content indicated that cold tolerance of Qingnong No.8 was the second among them.Nongdal08 and Zhengdan958 had different results in different physiological indexes.The SOD activity,POD activity and their rate of change,SP content and MDA content reflected that cold resistance of Nongda108 is better than Zhengdan958.However,other indicators including CAT activity and the change rate of it,MDA content and SP content reflected that cold resistance of Zhengdan958 was better than Nongda108.To sum extent this study provides a theoretical basis for the promotion of new maize variety Qingnong No.8 and the breeding of cold resistant varieties.