垂丝海棠应对盐碱复合胁迫的生理响应  

Study on Physiological Response of Malus halliana to Saline-alkali Stress

作　　者：贾旭梅 朱燕芳 王海 吴玉霞 赵通 程丽 朱祖雷 王延秀 JIA Xumei;ZHU Yanfang;WANG Hai;WU Yuxia;ZHAO Tong;CHENG LI;ZHU Zulei;WANG Yanxiu(College of Horticulture,Gansu Agricultural University,Lanzhou 730070,China)

机构地区：[1]甘肃农业大学园艺学院

出　　处：《生态学报》2019年第17期6349-6361,共13页Acta Ecologica Sinica

基　　金：甘肃省自然基金(18JR3RA171);学科建设专项基金(GAU-XKJS-2018-222)

摘　　要：盐碱复合胁迫是影响植物生长的主要环境因子。为了探究垂丝海棠(Malus halliana Koehen)响应盐碱复合胁迫的生理特性,利用主成分分析法明确耐盐碱阈值,以2年生垂丝海棠苗为试材,将NaCl与NaHCO3按1∶1的比例混合,通过盆栽浇灌Hogland营养液的方法,模拟5种不同浓度(0、50、100、150、200 mmol/L)盐碱复合胁迫对其光合色素、光合参数、叶绿素荧光参数及渗透调节物质的影响,并对其相关指标进行相关性和主成分分析。结果表明,随着胁迫强度的增大,叶绿素(Chl T)合成受阻,净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、胞间CO2浓度(Ci)、叶片含水量(WC)下降,最大光化学效率(Fv/Fm)、表观光合电子传递速率(ETR)、PSII实际化学效率(ΦPSII)、光化学猝灭系数(qP)被抑制;类胡萝卜素(Car)含量、水分利用效率(WUE)、电解质外渗率、非调节性能量耗散(Y(NO))升高;胁迫40 d时,初始荧光(F0)显著升高,而调节性能量耗散Y(NPQ)、非光化学荧光淬灭系数(qN)急剧降低;脯氨酸、可溶性糖、有机酸显著积累,并在100 mmol/L浓度下达到峰值。植株的Pn与Gs、Ci、ETR、ΦPSII呈极显著正相关,与Tr、WC、qP、Chl T呈显著正相关,与电导率、脯氨酸、Y(NO)呈显著负相关。因此,盐碱复合胁迫下,垂丝海棠叶片主要通过降低Gs、Ci、Tr、WC,提高WUE、大量积累渗透调节物质、启动热耗散机制来保持光合系统伤害与修复的动态平衡。根据主成分分析法,浓度100 mmol/L为耐盐碱阈值,同时Gs、Ci、Tr、Chl T、ETR、ΦPSII、Y(NO)、WC、qP、电解质渗透率、脯氨酸可作为评价垂丝海棠耐盐碱能力的有效指标。Saline?alkali stress is a major environmental factor limiting plant growth.To investigate physiological response of Malus halliana to saline?alkali stress and screen the threshold of saline?alkali tolerance,the characteristics of photosynthetic pigments,chlorophyll fluorescence parameters and osmolytes were studies and multiple indices were analyzed by correlation analysis and principal component analysis(PCA).Two?year?old of M.halliana was employed as experiment materials,and 5 different concentrations of saline?alkali stress(0,50,100,150,200 mmol/L)were simulated on the basis of NaCl and NaHCO3(1∶1)by pot experiment.The results showed that:with the increaseing of salt concentration,the chlorophyll content(Chl T),net photosynthesis(Pn),stomatal conductance(Gs),transpiration rate(Tr),intercellular CO2 concentration(Ci),leaf water content(WC),maximal photochemical efficiency(Fv/Fm),photosynthetic electron transport rate(ETR),actual photochemical efficiency(ΦPSII)and photochemical quenching coefficient(qP)were decreased,whereas the carotenoid content(Car),water use efficiency(WUE),electrolyte leakage rate and non regulatory energy dissipation(Y(NO))were increased.After 40 d stress,the initial fluorescence(F0)increased significantly but regulatory energy dissipation(Y(NPQ))and non photochemical quenching coefficient(qN)decreased significantly.However,the content of proline,soluble sugar and total organic acid remarkablely accumulated and reached the maximum at salinity 100 mmol/L.The Pn of M.halliana had a positive relation with Gs,Ci,ETR,ΦPSII,Tr,WC,qP and Chl T,while it correlated negatively with electrolyte leakage rate,proline and Y(NO).In summary,dynamic balance of photosynthetic system between injury and repair of M.halliana leaves was kept by reducing Gs,Ci,Tr and WC,increasing WUE,accumulating a large amount of osmotic regulators and starting heat dissipation mechanism under saline?alkali stress.Based on PCA,the concentration of 100 mmol/L was the critical threshold for saline?alkali tolerance.Moreover,t

关 键 词：垂丝海棠 耐盐碱能力 光合作用 叶绿素荧光 渗透调节 

分 类 号：S51[农业科学—作物学]