Cutting seedlings of amur grape (V .amurensis Rupr.)cultivars 'Shuangyou'(weak resistance) and 'Zuoshanyi'(strong resistance)were grown in plastic pots in shelter greenhouse.The effects of dif-ferent saline-alkali stress levels (light stress,moderate stress and severe stress)on photosynthetic charac-teristics and activities of photosystem Ⅱ (PS Ⅱ)in amur grape were studied using gas exchange and chlo-rophyll fluorescence induction dynamics analysis technology,and we surveyed their growth development.The results showed:(1)the net photosynthetic rate (Pn )and stomatal conductance (Gs )decreased signifi-cantly in lightly,moderately and severely stressed for 'Shuangyou'seedlings compared to control plants, but the transpiration rate (Tr )decreased significantly only under severe stress treatment.For 'Zuoshanyi' seedlings,Pn and Tr decreased significantly only under severe stress treatment,Gs decreased significantly under moderate and severe stress treatments,and intercellular CO2 concentration (Ci )decreased signifi-cantly under different stress treatments.The reduction of Pn was mainly caused by stomatal limitation and non-stomatal limitation.(2)The specific energy fluxes for absorption (ABS/RS),the density of QA- re-ducing PSⅡ reaction centers per cross section (RS/CS)and performance index (PIABS )decreased signifi-cantly in lightly and moderately stressed for 'Shuangyou'seedlings compared to control plants.For 'Zu-oshanyi'seedlings,ABS/RS ,RS/CS and the specific energy fluxes for electron transport (ETo/CS )de-creased significantly only under severe stress treatment,other parameters under different stress treatments were similar to control plants.(3)Sap flow rate,plant height,leaf number and root biomass had signifi-cant decrease under different treatments,and decrease rate of 'Shuangyou'was higher.In conclusion,for'Zuoshanyi'seedlings,saline-alkali stress has relatively little effect on Pn ,light energy absorption, electron transport efficacy and growth compared to 'Zuoshanyi',so 'Zuoshanyi'cultivar was more resist-ant to saline-alkali than 'Shuangyou'.For evaluation and detection of saline-alkali tolerance in amur grape,we not only need to evaluate some physiological parameters such as photosynthetic function,but also to evaluate comprehensive growth indexes.%以棚内盆栽山葡萄品种'双优'(抗逆性弱)和'左山一'(抗逆性强)扦插苗为材料,利用气体交换分析和叶绿素荧光诱导动力学分析手段,研究了轻度、中度和重度盐碱胁迫对不同抗逆性山葡萄品种的光合特性及PSⅡ活性以及生长发育的影响,为山葡萄耐盐碱品种的评价提供理论依据.结果显示:(1)'双优'各胁迫程度下的净光合速率(Pn)、气孔导度(Gs)和重度胁迫下的蒸腾速率(Tr)显著低于对照,而'左山一'重度胁迫下的Pn和Tr、中重度胁迫下的Gs、各胁迫程度下的胞间二氧化碳浓度(Ci)显著低于对照,净光合速率下降主要归因于气孔限制和非气孔限制.(2)轻度、中度盐碱胁迫'双优'叶片单位反应中心吸收的光能(ABS/RS)、单位面积内有活性反应中心数目(RS/CS)和吸收光能为基础的性能指数(PIABS),以及重度盐碱胁迫下'左山一'的ABS/RS、RS/CS、用于电子传递的光能(ETo/CS)均显著低于相应对照,其余均无显著变化.(3)2品种山葡萄植株茎流率及株高、叶片数和根系生物量等生长指标在不同盐碱胁迫水平下均比对照显著降低,并以'双优'品种降低幅度更大.研究表明,盐碱胁对山葡萄'左山一'的叶片净光合速率、PSⅡ光能吸收和传递效率以及生长的抑制作用均小于'双优','左山一'的耐盐碱性更强.
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