纽荷尔脐橙幼树对不同供磷水平光合响应.docVIP

纽荷尔脐橙幼树对不同供磷水平光合响应 　　摘 要：为探索不同供磷水平对纽荷尔脐橙[Newhall navel orange（Citrus sinensis Osbeck.）]幼树光合特性的影响，给幼龄脐橙果园磷肥的合理施用量提供科学依据，以枳砧纽荷尔脐橙幼树为材料，采用土培的方法研究了不同供磷水平条件下纽荷尔脐橙幼树叶片的光合速率日变化规律；不同供磷水平与光合速率、蒸腾速率、水分利用率的关系；不同供磷水平对光合色素含量的影响。结果表明，纽荷尔脐橙Pn日变化基本规律并不因供磷水平的高低而改变。供磷水平25 mg?kg-1的条件下，叶片中Chl.a、Chl.b和Car.含量也最高，全天的Pn都维持在最高水平，这一供磷水平最有利于纽荷尔脐橙发挥光合效率。不同供磷水平与纽荷尔脐橙叶片Pn、Tr和WUE之间表现出极显著的非线性一元二次回归关系。供磷水平低于或高于25 mg?kg-1，纽荷尔脐橙幼树叶片的Pn、Tr和WUE和Chl.a、Chl.b及Car.含量都极显著地降低了；供磷水平大于45 mg?kg-1对Chl.a、Chl.b合成和Pn的抑制作用要比低于25 mg?kg-1供磷水平的强得多。 　　关键词： 纽荷尔脐橙； 磷； 光合响应； 光合色素 　　中图分类号：Ｓ６６6．4 文献标志码：Ａ 文章编号：１００９－９９８０（２０12）０2－0166－０5 　　 　　Photosynthetic response to different phosphorus levels on young Newhall navel orange trees 　　FAN Wei-guo1，2，WANG Li-xin1，2 　　（1Guizhou Fruits Engineering Technology Research Centre， Guiyang， Guizhou 550025 China； 2Research Institute for Fruit Resources of Karst Mountain Region， Guizhou University， Guiyang， Guizhou 550025 China） 　　Abstract: To explore the effect of different phosphorus levels on photosynthesis characteristics of young Newhall navel orange（Citrus sinensis Osbeck.） trees and provide scientific foundation for the phosphorus application in navel orange orchard， potted young Newhall navel orange trees grafted on trifoliate were used to study the photosynthesis rate （Pn） daily change law under the condition of different phosphorus levels. The relationship between phosphorus levels and Pn， transpiration rate （Tr） and water-use efficiency （WUE） was also observed. The effect of different phosphorus levels on the content of photosynthetic pigment was investigated as well. The results showed that Pn daily change law did not change with phosphorus levels. Under 25 mg?kg-1 phosphorus level， Pn was always the highest on the whole day， and the contents of Chl.a， Chl.b and Car. were also the highest， so the level was the most favorable for photosynthesis in Newhall navel orange . In addition， there was extremely notable nonlinear quadratic regression relationship between phosphoru