干旱区栽培黑果枸杞光合特性和产量对施氮的响应

Effects of Nitrogen Application on Photosynthetic Characteristics and Yield of Lycium ruthenicum Murr.

为探明干旱区栽培黑果枸杞(Lycium ruthenicum Murr.)所需的最佳施氮量,采用单因素随机区组设计,在3个时期(头茬果期、夏果期、秋果期)5个施氮梯度(0、50 g·株^-1、100 g·株^-1、150 g·株^-1、200 g·株^-1),研究不同施氮量对干旱区种植的黑果枸杞光合特性和产量的影响。结果表明,适当施氮可以提高黑果枸杞叶片叶绿素(Chl)含量、净光合速率(Pn)、最大净光合速率(Pnmax)、蒸腾速率(Tr)、气孔导度(Gs)、水分利用率(WUE)、表观量子效率(AQY)、对弱光的利用能力、果实百粒质量、单株产量,并且能降低叶片胞间CO2浓度(Ci)。相关性分析表明,Chl含量与Ci间的相关性最为显著。当全年施氮量为150 g·株^-1时叶片Pn最高,3个时期分别比不施氮时高出67.6%、54.1%、44.0%;当全年施氮量为150或200 g·株^-1时果实单株产量最高,3个时期分别比不施氮时高出27.6%、32.9%和52.3%。说明当全年施氮量为150 g·株^-1时黑果枸杞叶片Pn最大,150或200 g·株^-1时果实产量最高。

In order to find out the optimal nitrogen application rate for the cultivation of Lycium ruthenicum Murr.Under single-factor randomized block design,five nitrogen application gradients(0,50 g·plant^-1,100 g·plant^-1,150 g·plant^-1,200 g·plant^-1)through three stages(initial fruit stage,summer fruit stage,and autumn fruit stage)was set to study the effects of different nitrogen rates on photosynthetic characteristics and yield of Lycium ruthenicum.The results showed that proper nitrogen application could increase chlorophyll(Chl)content,net photosynthetic rate(Pn),maximum net photosynthetic rate(Pnmax),transpiration rate(Tr),stomatal conductance(Gs),and water use efficiency(WUE),apparent quantum efficiency(AQY),100-grain mass,yield per plant,and the ability to use weak light and reduce intercellular CO2 concentration(Ci).Correlation analysis showed that the correlation between Chl content and Ci was the most significant.When the annual nitrogen application rate was 150 g·plant^-1,the Pnwas the highest,and it was 67.6%,54.1%and 44.0%higher than that of no nitrogen applicationat the three stages;when the annual nitrogen application rate was 150 g·plant^-1 or 200 g·plant^-1,the yield per plant was the highest,the maximum yield of single plant at the three stages was 27.6%,32.9%and 52.3%higher than that of no nitrogen application.It showed that the photosynthesis of Lycium ruthenicum was the maximum when the annual nitrogen application rate was 150 g·plant^-1,and the yield was maximum when the nitrogen application rate was 150 or 200 g·plant^-1.