[目的]探明24-表油菜素内酯(EBR)对抽蔓期菜豆植株涝渍和盐双重胁迫下多种生理指标的影响,为明确EBR的效用提供理论依据.[方法]以蔓生菜豆品种绿龙3号为材料,在塑料大棚内进行盆栽试验.于菜豆抽蔓期叶面喷施0.1 μmol/L EBR后,分别进行持续3 d盐胁迫(100 mmol/L NaCl)、涝渍胁迫(涝渍3 d)和涝渍+盐双重胁迫.胁迫后第10天观测菜豆幼苗的叶片长宽、光合色素、相对电导率、可溶性糖含量、光合参数、荧光参数以及光谱参数的变化情况.[结果]涝渍和盐双重胁迫菜豆叶片的长度和宽度显著降低,EBR使双重胁迫下菜豆叶片的长度、宽度和长宽比依次升高9.87%、8.26%和4.86%;盐胁迫或涝渍胁迫显著降低菜豆叶片的叶绿素a、叶绿素b、总叶绿素含量及类胡萝卜素含量,EBR+双重胁迫下叶绿素a/b比值显著升高34.36%;盐胁迫、涝渍胁迫和双重胁迫使菜豆叶片电导率分别升高35.93%、122.49%和17.51%,盐胁迫下菜豆叶片电导率在EBR缓解下显著下降49.47%;盐胁迫、涝渍胁迫和双重胁迫分别使菜豆的净光合速率降低52.71%、76.87%和90.53%,EBR可以缓解涝渍胁迫下光合速率的降低;喷施EBR使未经胁迫处理菜豆叶片的实际光合效率[Y(Ⅱ)]值和最大光合效率(Fv/Fm)值分别显著提高139.37%和81.86%,并缓解了涝渍胁迫下菜豆叶片Fv/Fm的降低;EBR增加了盐胁迫或涝渍胁迫下菜豆叶片的光化学反射指数(PRI)值.[结论]EBR的施加能够增强植物抗逆性,对盐、涝渍单胁迫和双重胁迫导致多项光合生理指标下降具有明显的缓解效应.
[Objective]The effects of 24-epibrassinolide(EBR)on physiological indexes of Phaseolus vulgaris L.at vining stage under waterlogging and salt stress were discussed to provide the theoretical basis for clarifying EBR effectiveness.[Method]The effects of 0.1 μmol/L EBR foliage spray at vining stage on leaf length,leaf width,photosynthetic pigments,relative conductivity,soluble sugar content,photosynthetic parameter,fluorescence parameter and spectrum parameter of common bean variety(Lvlong3)under 3 d salt stress(100 mmol/L NaCl),3 d waterlogging stress and 3 d salt+3 d waterlogging stress were determined after 10 d by a pot experiment in greenhouse.[Result]The waterlogging+salt stress reduced leaf length and width of P.vulgaris significantly but EBR could increase leaf length,width and length/width ratio of P.vulgaris by 9.87%,8.26%and 4.86%respectively.The salt stress or waterlogging stress both reduced leaf chlorophyll a,chlorophyll b,total chlorophyll and carotenoid content of P.vulgaris significantly.The chlorophyll a/b ratio under EBR+double stress rose by 34.36%.The leaf conductivity of P.vulgaris under salt stress,waterlogging stress and double stress rose by 35.93%,122.49%and 17.51%separately.The leaf conductivity under salt stress decreased by 49.47%under EBR alleviation.The leaf net photosynthetic rate of P.vulgaris reduced by 52.71%,76.87%and 90.53%under salt,waterlogging and double stress respectively.EBR could alleviate the decrease of leaf net photosynthetic rate of P.vulgaris under waterlogging stress.The EBR increased leaf Y(Ⅱ)and Fv/Fm of P.vulgaris without any stress treatment by 139.37%and 81.86%respectively and alleviated the decrease of leaf Fv/Fm of P.vulgaris under waterlogging stress.The EBR increased the leaf photochemistry reflect index of P.vulgaris under salt stress or waterlogging stress.[Conclusion]Spraying EBR could improve plant adverse resistance and had the obvious alleviation effect on decrease of multiple leaf photosynthetic physiological indexes of P.vulgaris under salt stress,waterlogging stress and salt+waterlogging stress.