Effects of phosphorus levels on chlorophyll fluorescence parameters of wheat (Triticum aestivum L.) with different phosphorus efficiencies

The effects of phosphorus levels (0, 10, 100, 500 and 1000 μmol/L) on the chlorophyll fluorescence parameters and chlorophyll content of the proximal first leaves of wheat (Triticum aestivum L.) seedlings with different phosphorus efficiencies (Xinong 979 and Xiaoyan No. 6) were studied using the culture solution. The results showed that Chl.a fluorescence parameters of the first leaves of wheat seedlings increased at first and then declined under the increase of phosphorus levels. The maxima of Xinong 979 were under the 500 μmo/L phosphorus level, while those of Xiaoyan No.6 were under 100 μmol/L phosphorus level. This illustrates that the efficiency of light energy transformation and electron transportation of Xiaoyan No.6 (high phosphorus efficiency) are higher than those of Xinong 979, and are less affected by low P stress.