Effects Of Oxygen-nitrogen Interaction On Root Growth And Nitrogen Uptake And Utilization Of Super Rice

The absorption of nitrogen by the root system is closely related to the oxygen content of the root environment.In order to explore the influence of super rice roots on nitrogen uptake and utilization under aerobic conditions,and to reveal the synergistic mechanism of oxygenation and nitrogen application,this experiment set two factors of oxygenation and nitrogen application through hydroponics,analyzed the physiological indexes of root system,root nitrogen metabolism and nitrogen accumulation,root antioxidant and other related indicators,studied the synergistic influence of oxygen-nitrogen interaction on root growth of super rice,and revealed the physiological response mechanism of super rice root system to oxygen-nitrogen interaction from the root physiological and biochemical level.Thus providing ideas for the efficient cultivation mode of super rice in China.The main findings are as follows:(1)Oxygen-nitrogen interaction significantly improved the root morphological indexes such as root length,root surface area and number of branches of rice,and enhanced root vitality.The root viability under O2 MN treatment was increased by 70.20% and 90.05%respectively compared with CK at the tillering stage and the gestational panicle stage.(2)Oxygen-nitrogen interaction is conducive to enhancing NR and GS enzyme activities,promoting the absorption and utilization of nitrogen by roots,thereby increasing root nitrogen accumulation.The amount of root nitrogen accumulation under O2 MN treatment increased by 38.89% and 82.56% respectively compared with CK at the tillering stage and maturity stage.(3)Oxygen-nitrogen interaction is conducive to improving root SOD activity,reducing MDA content,increasing soluble sugar content,delaying the aging rate of roots in the late growth stage,and maintaining high root vitality.(4)Oxygen-nitrogen interaction significantly affects the effective panicle number,total grain count,seed setting rate and 1,000 grain weight of super rice,and promotes the accumulation of aboveground biomass and total biomass.The yield under O2 MN treatment increased by 53.19% compared with CK.