摘要
为了探讨碱蓬和三角叶滨藜对不同盐度的响应机制,采用砂培试验,用含不同浓度NaCl的Hoagland营养液处理其幼苗30d,分析其生物量、株高、含水量(WC)、叶绿素(Chl)含量、类胡萝卜素(Car)含量、Chl/Car、Chl a/Chl b、净光合速率(Pn)、气孔导度(Gs)、细胞间CO2浓度(Ci)、蒸腾速率(Tr)、水分利用效率(WUE)和气孔限制值(Ls)的变化。结果表明,1)和对照(不加NaCl)相比,低盐(100mmol/L NaCl)显著提高碱蓬幼苗的干重(DW)、株高和地上部WC,三角叶滨藜的株高不受明显影响,而其地上部DW和WC显著下降;中盐(400mmol/L NaCl)胁迫下,碱蓬株高、地上部DW和WC无显著变化,而三角叶滨藜地上部DW和WC显著下降;高盐(800mmol/LNaCl)下,两植物DW和含水量均明显降低,且碱蓬干重和含水量的降幅要显著低于三角叶滨藜。2)低盐对两植物的Chl含量没有明显影响,随着盐度的增加,其Chl含量均显著下降,碱蓬Chl含量的降幅显著大于三角叶滨藜。低盐明显提高碱蓬叶片的Car含量,但是不影响三角叶滨藜叶片的Car含量,随着盐度的增加,两植物的Car含量均显著下降,碱蓬Car含量的降幅显著大于三角叶滨藜的。随着NaCl浓度增加,两植物的Chl a/Chl b均逐渐上升,而对三角叶滨藜的Chl/Car影响也不显著,但是随着盐度的增加,碱蓬叶片Chl/Car呈先降低后升高的趋势。3)100mmol/L NaCl处理显著提高碱蓬的Pn、Gs和Tr,但显著降低三角叶滨藜的Pn、Gs和Tr,随着盐度的进一步增加,二者的Pn、Tr、Gs均显著下降,其中碱蓬Pn、Tr的降幅要显著低于三角叶滨藜的。随着盐度的增加,碱蓬Ci逐渐显著下降;而随着盐度增加,三角叶滨藜的Ci呈先降低、再升高的趋势,800mmol/L NaCl处理的Ci显著高于对照。4)碱蓬生物量与Tr、Pn、地上部WC、Car含量、根WC、Gs、根冠比、株高、Chl含量、Ci有极显著的正相关,而与Chl/Car、Ls呈极显著负相关,与WUE显著负相关;三角叶滨藜生物量与地上部WC、Chl含量、Pn、Car含量、Tr、Gs、根WC、株高呈极显著正相关,与Chl a/Chl b呈极显著负相关。综上所述,碱蓬和三角叶滨藜幼苗具有高度的耐盐性,且前者的耐盐性高于后者,主要是因为高盐下前者维持更高的光合效率和水分利用效率;Tr、Pn和地上部WC可优先作为评价碱蓬耐盐性的指标,而可作为优先评价三角叶滨藜耐盐性的指标为地上部WC、Chl含量和Pn;高盐下碱蓬Pn的下降主要是气孔限制的结果,而三角叶滨藜Pn下降则主要是由于非气孔限制导致的。
In order to get the response mechanism of Suaeda glauca and Atriplex triangularis to different salinity level,we investigated the alteration of different concentrations of NaCl with Hoagland solution on plant biomass,height,water content(WC),chlorophyll(Chl) content,carotenoid(Car) content,Chl/Car,Chl a/Chl b,Pn,Gs,Ci,Tr,water use efficiency(WUE) and stomatal limitation(Ls) in S.glauca and A.triangularis seedlings in this study.1) Compared with control,treatment with 100 mmol/L NaCl significantly increased the dry weight,height and shoot WC of S.glauca plant,however,100 mmol/L NaCl did not affect the plant height of A.triangularis,decreasing its shoot dry weight and WC markedly.Treatment with 400 mmol/L NaCl had no effect on the shoot dry weight(DW) and WC of S.glauca,but it heavily reduced shoot DW and WC of A.triangularis.With salinity of 800 mmol/L NaCl,DW and WC of two plants were decreased significantly,and the decrease of A.triangularis was much more than that of S.glauca.2) Treatment of 100 mmol/L NaCl did not affect the Chl content,and treatments of 200 and 400 mmol/L NaCl significantly decreased the Chl content in both two plants.However,the decrease was much more significantly in S.glauca than that in A.triangularis under 200 and 400 mmol/L NaCl.Treatment of 100 mmol/L NaCl significantly increased the Car content of S.glauca,but did not affect the Car content of A.triangularis.Treatments of 200 and 400 mmol/L NaCl significantly decreased the Chl content in both two plants.Similarly,the decrease was much more significantly in S.glauca than that in A.triangularis.All NaCl treatments did not affect Chl a/Chl b in both plants and Chl/Car in A.triangularis,but Chl/Car in S.glauca was descended in first and ascended at last as NaCl concentrations rising.3) We found that values of Pn,Gs and Tr in S.glauca were all ascended under treatment with 100 mmol/L NaCl,while 100 mmol/L NaCl significantly decreased the Pn,Gs and Tr in A.triangularis.Under stresses of 200 and 400 mmol/L NaCl,Pn,Gs and Tr were significantly decreased in both two plants.However,Pn and Tr were decreased more significantly in A.triangularis than in S.glauca.With the increase of salinity,the Ci value in S.glauca was gradually decreased.Meanwhile,in A.triangularis,the Ci value was descended in first and then ascended,and Ci in the treatment of 800 mmol/L NaCl was obviously higher than that in the control.4) Biomass of S.glauca showed highly significant positive-correlation with its Tr,Pn,shoot WC,Car content,root WC,Gs,root shoot ratio,plant height,Chl content and Ci,and showed highly significant negative-correlation with its Chl/Car and Ls.For A.triangularis,its biomass was highly significant positive-correlation with shoot WC,Chl content,Pn,Car content,Tr,Gs,root WC and plant height,but highly significant negative-correlation with Chl a/Chl b.To sum up,S.glauca and A.triangularis both have high salt resistance.Compared with A.triangularis,S.glauca having better adaptation to salt was owing to maintaining higher photosynthetic and water use efficiency.Under severe salt stress,the reduction in photosynthesis of S.glauca was mainly due to stomatal limitations,while for A.triangularis,the reduction in its photosynthesis was mainly due to non-stomatal limitations.
出处
《草业学报》
CSCD
北大核心
2012年第6期64-74,共11页
Acta Prataculturae Sinica
基金
浙江省重大科技专项(2012C12017-3)
南京农业大学SRT项目(1113A28)
浙江省科技项目(2010F20007)
山东省黄河三角洲生态环境重点实验室开放基金(2011KFJJ02)
江苏省自然科学基金青年基金项目(BK2012073)资助
关键词
碱蓬
三角叶滨藜
幼苗
耐盐性
光合特性
Suaeda glauca
Atriplex triangularis
seedlings
salt resistance
photosynthetic characteristics