| 摘要: |
| 【目的】探讨外源亚精胺（Spd）对盐碱胁迫下番茄（Solanum lycopersicum L.）幼苗叶片光合特性的调控效应，以从光合调控的角度评价Spd对番茄幼苗耐盐碱性的作用机制。【方法】采用水培法，以抗盐碱性不同的2个番茄品种‘中杂9号’（耐性较弱品种）和‘金棚朝冠’（耐性较强品种）为试验材料，每个品种随机分成4组进行不同处理（对照，1/2倍Hoagland营养液+叶面喷蒸馏水；单纯盐碱胁迫处理，75 mmol/L盐碱溶液+叶面喷蒸馏水；单纯喷施亚精胺（Spd）处理，1/2倍Hoagland营养液+叶面喷0.25 mmol/L Spd；盐碱+喷施Spd处理，75 mmol/L盐碱溶液+叶面喷0.25 mmol/L Spd），研究盐碱胁迫下外源Spd对番茄幼苗地上部干鲜质量、叶绿素含量、净光合速率（Pn）、蒸腾速率（Tr）、瞬间水分利用率（WUE）、气孔导度（Gs）、胞间CO2浓度（Ci）和气孔限制值（Ls）的影响。【结果】与对照相比，单纯喷施Spd处理对‘中杂9号’幼苗地上部鲜质量、叶绿素含量以及‘金棚朝冠’幼苗地上部干鲜质量、叶绿素a/b均有显著促进效应（P<0.05），同时对‘中杂9号’Gs和Ci有显著抑制效应（P<0.05）。与对照相比，单纯盐碱胁迫处理‘中杂9号’幼苗地上部干鲜质量、叶绿素含量、叶绿素a/b、Pn、Tr、WUE、Gs、Ls以及‘金棚朝冠’幼苗地上部干质量、叶绿素含量、叶绿素a/b、Pn、Tr、Gs、Ci均显著降低（P<0.05），其中‘中杂9号’和‘金棚朝冠’的Pn分别降低68.0%和48.1%，同时‘中杂9号’的Ci以及‘金棚朝冠’的Ls均显著升高（P<0.05）。与单纯盐碱胁迫处理相比，盐碱+喷施Spd处理显著提高了2个番茄品种的地上部干质量、叶绿素含量、Pn、Tr、WUE、Gs（P<0.05），表明叶面喷施Spd可以有效缓解叶绿素降解，降低盐碱胁迫对番茄叶片光合作用的气孔限制或非气孔限制，显著增加盐碱胁迫下叶片的瞬间水分利用率（‘中杂9号’和‘金棚朝冠’的WUE分别提高13.3%和10.4%），且对‘中杂9号’的效应更为明显。【结论】叶面喷施Spd可以提高番茄幼苗的耐盐碱性，有利于促进盐碱胁迫下番茄植株的生长，这种促进作用与Spd对光合机构的保护效应密切相关。 |
| 关键词: 番茄 亚精胺 光合作用 盐碱胁迫 |
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| 基金项目:国家自然科学基金青年科学基金项目（31501807,31101581）；山西农业大学引进人才博士科研启动费项目（2013YJ20） |
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| Effects of exogenous spermidine on photosynthetic characteristics of tomato seedlings under salinity-alkalinity stress |
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ZHANG Yi,SHI Yu,HU Xiao-hui
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| Abstract: |
| 【Objective】This study investigated the regulation effects of exogenous spermidine (Spd) on photosynthetic characteristics of tomato (Solanum lycopersicum L.) leaves under salinity-alkalinity stress.【Methods】Two tomato cultivars with different saline-alkaline resistances,‘Jinpengchaoguan’ (with higher resistance) and ‘Zhongza 9’ (with lower resistance),were planted using water culturing method.The seedlings of each cultivar were randomly divided into four groups (control:half strength Hoagland nutrient solution and spraying with distilled water;single saline-alkaline treatment:seedlings were exposed to half strength Hoagland nutrient solution containing 75 mmol/L saline-alkaline solution and spraying with distilled water;single Spd treatment: half-strength Hoagland nutrient solution and spraying with 0.25 mmol/L Spd;and saline alkaline plus Spd treatment:seedlings were exposed to half-strength Hoagland nutrient solution containing 75 mmol/L saline-alkaline solution and spraying with 0.25 mmol/L Spd).The influences of exogenous Spd (foliar spraying) on the fresh and dry biomass of shoots,leaf chlorophyll contents,net photosynthetic rates (Pn),transpiration rates (Tr), water use efficiencies (WUE),stomatal conductances (Gs), intercellular CO2 concentrations (Ci),and stomatal limitation values (Ls) in tomato seedlings were then analyzed.【Results】Compared with control,shoot fresh weight and leaf chlorophyll content of ‘Zhongza 9’,as well as chlorophyll a/b,shoot fresh and dry weight of ‘Jinpengchaoguan’ were significantly increased by single Spd treatment,while Gs and Ci of ‘Zhongza 9’ were significantly decreased by exogenous Spd (P<0.05).Ci of ‘Zhongza 9’and Ls of ‘Jinpengchaoguan’ were significantly increased under single salinity alkalinity stress (P<0.05),while shoot fresh and dry weight,leaf chlorophyll content,chlorophyll a/b,Pn,Tr,WUE,Gs and Ls of ‘Zhongza 9’,as well as shoot dry weight,leaf chlorophyll content,chlorophyll a/b,Pn,Tr,Gs and Ci of ‘Jinpengchaoguan’ were significantly decreased by single saline-alkaline treatment (P<0.05).The decreases in Pn of ‘Zhongza 9’ and ‘Jinpengchaoguan’ reached 68.0% and 48.1%,respectively.In comparison with the single saline-alkaline treatment,exogenous Spd increased shoot dry weight,leaf chlorophyll content,Pn,Tr,WUE and Gs of ‘Zhongza 9’ and ‘Jinpengchaoguan’ seedlings exposed to salinity alkalinity stress significantly (P<0.05),indicating that exogenous Spd could alleviate the degradation of chlorophyll,reduce the stomatal or non-stomatal limitation of salinity-alkalinity stress on leaf photosynthesis,and improve the leaf WUE of tomato seedlings exposed to salinity-alkalinity stress.The increases leaf WUE of in ‘Zhongza 9’ and ‘Jinpengchaoguan’ were 13.3% and 10.4%,respectively.The effects were more significant in ‘Zhongza 9’.【Conclusions】Foliar spraying Spd can improve the salinity alkalinity tolerance of tomato seedlings,and benefit the growth of plants under salinity alkalinity stress.The promotive functions are closely related to the protective effects of Spd on photosynthetic apparatus. |
| Key words: tomato spermidine photosynthesis salinity-alkalinity stress |
