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Response of Photosynthetic Characteristics of Walnut Seedlings to High Phosphorus Stress
LIU Chunhua, ZHANG Rui,XIE Fu,WANG Yang,HU Kaihong,WANG Jianjian SONG Yan,ZHAO Zhenkun,ZHANG Jianliang
2021, 58(2):
254-264.
DOI: 10.6048/j.issn.1001-4330.2021.02.007
【Objective】 To reveal the photosynthetic physiology and material accumulation characteristics of walnut rootstock seedlings under high phosphorus stress in the hope of providing a reference for the application and management of phosphate fertilizer on walnut seedlings.【Method】 Xinxin 2 walnut seedlings were taken as research materials, and the biomass, photosynthetic characteristics, fluorescence characteristics, photosynthetic products and nutrient elements of walnuts were compared under high phosphorus gradient.【Result】 The results showed that the overall biomass of walnut seedlings showed a downward trend with the increase of phosphorus application. Net photosynthetic rate, stomatal conductance, intercellular CO2 concentration, transpiration rate, initial fluorescence, maximum fluorescence, maximum photochemical quantum efficiency, and light and pigment increased first and then decreased, and reached the peak value under P2 treatment. Soluble sugars and soluble proteins synthesized by different phosphorus levels in walnut seedlings increased with the increase of phosphorus gradient, and acid phosphatase activity decreased. Sulfur, potassium, molybdenum, zinc, boron, and iron elements in walnut rootstock seedlings increased first and then declined with the increase of phosphorus supply level, and reached a peak under P2 treatment. The phosphorus, magnesium, calcium, copper, and manganese elements followed the phosphorus level. It increased with the increase of P and reached the maximum value under P4 treatment, which indicated that excessive phosphorus was not conducive to the absorption of the above elements by walnut seedlings.【Conclusion】 High phosphorus stress significantly, inhibited the growth and photosynthesis of walnut seedlings, and broke the balance between the nutrient contents of the walnut seedlings. Too high or too low phosphorus is not conducive to the growth and development of walnut seedlings.
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