不同氮素籽粒生产效率油菜品种苗期叶片光合特性差异

2007-2008年度通过对不同氮肥水平下28个品种苗期叶片叶绿素含量和光合参数以及氮素籽粒生产效率的测定，结果表明：（1）不同品种氮素籽粒生产效率差异较大，施用氮肥氮素籽粒生产效率显著降低。（2）多数品种施用氮肥叶片叶绿素含量(SPAD值)，净光合速率(Pn)增加；PSⅡ最大光化学量子产量(Fv/Fm)，光化学淬灭系数(qP)增加，非光化学淬灭系数(qN)减小。（3）叶片叶绿素含量(SPAD值)与净光合速率(Pn)之间，净光合速率(Pn)与PSⅡ最大光化学量子产量(Fv/Fm)之间都表现显著正相关关系。（4）氮素籽粒生产效率与苗期叶片PSⅡ最大光化学量子产量(Fv/Fm)呈显著正相关，不施氮肥条件下氮素籽粒生产效率与SPAD值呈显著正相关。

Differences of Photosynthetic Characteristics in Rapeseed (Brassica napus.L) at Seedling Stage with Different Nitrogen Utilization Efficiency for Grain Production

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.