Abstract:

In this study, 28 conventional rapeseed (Brassica napus.L) cultivars were cultured in and 2007-2008. Through testing SPAD values and photosynthetic characteristics of leaf at seeding stage, and testing nitrogen use efficiency for grain production (NUEg) at ripening stage. The main results were as follows: (1)Difference of NUEg was significant in all cultivars, with the increasing of fertilization NUEg decreased significantly. (2)In most cultivars with the increasing of fertilization SPAD values, maximal photochemical efficiency of photosystemⅡ(Fv/Fm), and photochemical quenching coefficient (qP) increased, but non-photochemical quenching coefficient (qN) decreased. (3)There was significant positive correlation between SPAD values and net photosynthetic rate (Pn), and there was significant positive correlation between Pn and Fv/Fm. (4) There was significant positive correlation between NUEg and Fv/Fm, and under no nitrogen fertilization NUEg was significant positive correlated with SPAD values.