The Agronomic And Biological Response Mechanism To Nitrogen Supply Of Maize Differing In Different Nitrogen Efficiency

In this study, combined with the field experiment and nutrient solution culture experiment was carried out to study the effect of different N supply on senescence of different N efficiency maize,through researching for the influence of the nitrogenous fertilizer amount used to the different nitrogen efficiency corn to the material accumulation and the nitrogen absorption; to the dynamic change of oxygen free radical eliminating essential enzyme,such as Peroxidase (POD), Catalase (CAT), Superoxide dismutase (SOD) activity. Ascorbate peroxidase (POD) and the membrane electron particle materialization; and researching for the different nitrogen efficiency corn senile signal gene's expression that under the nitrogen non-balanced and the influnce of different extraneous source hormone to the different nitrogen efficiency maize exsomatize leaf active oxygen and the membrane electron particle materialization's. It is showed that agronomy and the biology response mechanism of different nitrogen efficiency corn to the nitrogen non-balanced supply, which can estabilish the theory basis for how to regulate the leaf blade senile advancement under the non-balanced nitrogen for the different nitrogen efficiency corn, make early forecasts and propose reasonable measure.In the field experiment, the different N efficiency maize performed different in different nitrogen supply. With increasing N applying, the biomass and N uptake in both varieties were increase significantly. The N response of Xianyu335 was higher than Sidan19, and with much higher yield. Due to the date of highest biomass accumulation rate in Xianyu335 was later than in Sidan19, so more growth activity was obtained in the later growth stage to supply enough nutrients to grain. In N2 treatment, the date of highest biomass accumulation rate was delayed. In addition, the green leaf rate has the significantly positive relationship with yield. The nitrogen use efficiency, N physiological efficiency and N agronomic efficiency and N partial factor productivity were higher in Xianyu335 than in Sidan19.In different aging stages, the response of POD, CAT and SOD activity in ear leaf to nitrogen is different. Before tasseling, POD activity of ear leaf decreased with the N application increasing, but in 26 days after tasseling, the trend of POD activity was changed. N application can increase the CAT activity of ear leaf in both varieties. But the SOD activity is reduced with N increasing.From see 1 and see 2 express situation, by see2 gene expression of the effect of nitrogen and aging is not clear. In 13 days after tasseling 19 of the four single significantly higher than see 1 express quantity first jade 335.Through nutrient solution culture experiment was used to research the different exogenous hormones on reactive oxygen and membrane of leaves in Vitro leaves of different N efficiency maize. After ABA treatment of leaf of corn, MDA and H2O2 content is increasing, Three protective enzymes SOD,POD and CAT activity in active-oxygen scavenging system were significantly strengthen of stay green type, it is illustration the ABA caused peroxidation intimidation And compared with three types of corn, the green of maize leaf MDA content is low, difference is remarkable. And Non-stay green type corn varieties leaves appear above the green violation peroxide level of maize, the content of MDA and H2O2 accumulated earlier than Xianyu 335.6-BA could delay the addition of SOD isozyme bands and the weakening of isozyme strengty.6-BA could prevent MDA accumulation caused by H2O2.