中文摘要：

为明确烯效唑在减轻大豆淹水胁迫伤害中的生理作用,本研究以耐涝品种垦丰14和涝渍敏感品种垦丰16为试验材料,采用盆栽方式,在三节期（V3）叶面喷施50mg/L烯效唑,之后进行淹水胁迫,于三节期（V3）、淹水3d（V3-3d）、淹水5d（V3-5d）以及恢复正常水分条件后（始花期R1、始荚期R3、始粒期R5期）测定叶片光合参数,分析烯效唑对淹水胁迫下大豆叶片叶绿素相对含量、光合特性及产量的调控效应。结果表明：淹水胁迫期间（V3-3d~V3-5d）,垦丰16叶片光合特性各指标的降低幅度高于垦丰14;恢复正常水分处理后,垦丰14较垦丰16具有较强的补偿效应,表现为叶片净光合速率显著提高。与喷施清水进行对比,喷施烯效唑能提高淹水胁迫期间大豆叶片净光合速率、蒸腾速率、气孔导度和胞间CO2浓度,并且在恢复正常水分管理后,已喷施烯效唑的大豆叶片SPAD值、光合特性指标高于正常水分处理。淹水胁迫条件下喷施烯效唑处理使垦丰14的单株产量较正常水分、喷施清水处理分别高105.81%、28.17%,使垦丰16单株产量分别提高10.16%、23.93%。说明喷施烯效唑可有效改善淹水胁迫下大豆叶片光合特性,从而增加其单株产量,且不同品种对烯效唑的调控效应存在差异。

英文摘要：

In order to clarify the physiological role of S3307 in reducing the damage of soybean 1flooding stress,effects of uniconazole on leaf photosynthetic characteristics and yield of soybean under waterlogging stress were studied. A pot experiment with 2 soybean varieties Kenfeng 14（waterlogging-tolerant） and Kenfeng 16（waterlogging-sensitive） was conducted,and leaf photosynthetic characteristics were determined in V3,V3-3d（flooding 3d）,V3-5d（flooding 5d）,and rewater conditions（R1,R3,R5）,to analyze the regulation effect of spraying uniconazole on the relative chlorophyll content,photosynthetic indexes,and yield per plant under waterlogging stress. The results showed that reduction of leaf net photosynthetic rate（Pn）,transpiration rate（Tr）,stomatal conductance（Gs） and intercellular CO2concentration（Ci） in Kenfeng 16 were greater than those of Kenfeng 14 during the waterlogging stress period（V3-3d to V3-5d）; leaf Pn in Kenfeng 14 increased significantly in comparison to Kenfeng 16 under rewater conditions. Compared with spraying water,uniconazole could improve the leaf Pn,Tr,Gs and Ci under waterlogging stress. Moreover,leaf SPAD,photosyn thetic indexes in uniconazole were higher than those with normal water（CK） treatment. The yield per plant of Kenfeng 14 in uniconazole under waterlogging stress was increased by 105. 81% and 28. 17% compared with spraying water under waterlogging stress and CK respectively,and the increases were 10. 16% and 23. 93% in Kenfeng 16. Therefore,spraying uniconazole improved the leaf photosynthetic characteristic,resulting in higher yield per plant under waterlogging stress,but the sensitivity of different soybean varieties was different.