Eco-physiological mechanism on nitrogen use efficiency difference of corn varieties

By use of field experiments and pot culture experiments, seed yield per day, nitrogen absorption efficiency, root morphology, leaf nitrate reductase (NRA), canopy photosynthesis eco physiological characteristics etc. were studied with 7 different corn varieties The results showed that 5 varieties of DK743, DK656, YY22, ZD2 and HD1 had high nitrogen use efficiency (NUE), but another two varieties of JD2 and SY905 had low NUE NUE were correlated with root dry weight, root length, root surface area, leaf NRA, net photosynthetic rate (Pn), stoma resistance(Sr) etc Pn, Sr, leaf NRA, total dry matter, seed yield were increased by more N applying, and the range of increasing were different among 7 varieties