Effect of Low Nitrogen Stress on the Seedling Growth and Root Physiological Traits of Fagopyrum tataricum Cultivars with Different Low-N Treatments
ZHANG Chu;ZHANG Yongqing;LU Zhijuan;LIU Liqin;YANG Chunting;College of Life Science,Shanxi Normal University;College of Geographical Science,Shanxi Normal University;
In order to reveal the physiological response mechanism of Fagopyrum tataricumto low nitrogen(N)stress,were conducted the pot experiment to study the effects of low N stress on the seedling growth,root physiological traits and nitrogen uptaking.The experimental materials included 2low-N tolerant cultivars(‘Diqing kuqiao',‘Guangku 1')and 2low-N sensitive cultivars(‘Xiqiao 1',‘Heifeng 1').Three results were drawn from the this experiment.(1)Compared to the normal N treatment(15mmol/L),the plant height,stem diameter,leaf area,shoot dry weight,root diameter,root volume and root area weredeclined,root/shoot ratio and main root length were increased under low-N stress(0.5mmol/L)and very low-N stress(0.05mmol/L).Besides,the root dry weight increased to a certain stress extent under lowN stress,and the amplification of low-N tolerant cultivars was more bigger(13.69% and 19.26%);(2)Low-N stress could make leaf chlorophyll content,Fm,Fv/Fm,root activity,nitrate reductase(NR)activity and soluble protein content significantly decreased,but make Fo,root superoxide dismutase(SOD)activity,peroxidase(POD)activity,malonaldehyde(MDA)content,soluble sugar content and free proline content increased;(3)Plant N content and plant N uptake significantly decreased under low-N stress,while plant N uptake efficiency increased.The study has shown that the different F.tararicumcultivars to low-N stress were significantly different.Under low N environment,low-N tolerant cultivars had the obvious advantages of growth not only because the less influence of low N pressure to agronomic character,photosynthesis and root activity,but also because the higher root protective enzyme activity,osmotic adjustment substances contents,plant N contents and plant N uptake.
【Key Words】： Fagopyrum tataricum low nitrogen stress seedling stage morphological characteristics physiological parameters
【CateGory Index】： S517
【CateGory Index】： S517