Ju Zhengchun, Yu Zhenwen
Key Laboratory of Wheat Cultivation Physiology and Genetic Improvement of Agriculture Ministry, Shandong Agricultural University, Taian 271018, China.
Ying Yong Sheng Tai Xue Bao. 2006 Mar;17(3):395-8.
With field experiment, this paper studied the effects of nitrogen topdressing at different growth stage on the chlorophyll fluorescence and photosynthetic rate of winter wheat flag leaves, and on the grain yield of the wheat. Compared with that at getting-up and flagging stages, nitrogen topdressing at jointing stage improved the PSII (Fv/Fo) activity, maximum photochemical efficiency (Fv/Fm,), PSII coefficient of photochemical fluorescence quenching (qP), actual quantum yield of PSII electron transformation (phiPS II), and photosynthetic rate of flag leaves, and made the dissipation of non-radiant energy lower at early and middle filling stage, and higher at late filling stage, which made it possible for flag leaves to absorb more light energy for photosynthesis at early and middle filling stage, and reduce the light inhibition extent and senescence at late filling stage. Nitrogen topdressing at jointing stag increased the spikes and grain weight per kernel, resulting in the highest grain yield.
通过田间试验，研究了不同生育时期追施氮肥对冬小麦旗叶叶绿素荧光、光合速率及小麦籽粒产量的影响。与起身期和拔节期追施氮肥相比，拔节期追施氮肥提高了旗叶PSII（Fv/Fo）活性、最大光化学效率（Fv/Fm）、PSII光化学荧光猝灭系数（qP）、PSII电子传递实际量子产额（phiPSII）和光合速率，使灌浆前期和中期非辐射能量耗散降低，灌浆后期升高，从而使旗叶在灌浆前期和中期能吸收更多光能用于光合作用，在灌浆后期降低光抑制程度并延缓衰老。拔节期追施氮肥增加了穗数和单粒重，籽粒产量最高。
