磷素水平对不同大豆品种叶片及子粒谷氨酰胺合成酶活性的影响

盆栽试验选用东农42（高蛋白品种）、合丰25（中间型品种）、东农46（高油品种）3个基因型大豆品种，在每千克土壤施N和K2O各为0.033g基础上，设P0、P5、P10、P15 4个P处理（即每kg土壤分别施P2O5 0、0.033、0.067、0.100g），研究了不同磷素水平对大豆生育期功能叶片及子粒谷氨酰胺合成酶（GS）活性的影响。结果表明，东农42和合丰25均为P10处理功能叶片和子粒GS活性最高；东农46为P10处理功能叶片GS活性最高，P5处理子粒GS活性最高。同一处理不同品种间东农42功能叶片和子粒GS活性最高，东农46最低，合丰25处于二者之间；3个品种不同处理功能叶片GS活性最高值均出现在结荚期，东农42子粒GS活性处于高值时间较长，东农46最短，合丰25处于二者之间。施磷对3个大豆品种叶片及子粒GS活性有影响，适宜的施磷量有利于提高其活性。

Effect of phosphorus level on glutamine synthetase activities in leaves and seeds of different soybean cultivars

This article mainly discussed the effect of phosphorous levels on the glutamine synthetase (GS) activities in soybean functional leaves at different growth stages and soybean seeds. Three soybean genotypes were used, including Dongnong 42 (high protein cultivar), Hefeng 25 (middle cultivar) and Dongnong 46 (high oil cultivar). The soybean seeds were planted in pots and fertilized with 0.033 g of N and K₂O per kg soil. Four levels of phosphorous treatments were designed, which were P₀, P₅, P₁₀ and P₁₅ (i.e., 0, 0.033, 0.067 and 0.100 g of P₂O₅ per kg soil). The results showed that the highest GS activity in functional leaves and seeds of Dongnong 42 and Hefeng 25 appeared under P₁₀ treatment; while in Dongnong 46, the highest GS activity in functional leaves was determined under P₁₀ treatment and that of seeds was detected under P₅ treatment. In the same treatment among cultivars, the highest GS activity in functional leaves and seeds was in Dongnong 42, the lowest one was in Dongnong 46 and Hefeng 25 was in the middle of the three cultivars. In each cultivar under each treatment, the highest value of GS activities in functional leaves was all determined at pod setting stage. The highest values of GS activities in seeds could be maintained much longer in Dongnong 42, but could be maintained shorter in Dongnong 46. The phosphorous treatment has an effect on the GS activities of leaves and seeds，and an appropriate phosphorous treatment is beneficial to improving GS activities.