The Role of Calcium Tolerance of Kandelia obovata(S.,L.) Yong

目前，红树林湿地面临越来越严重的重金属污染，红树林湿地重金属污染的修复近年来成为研究热点，然而红树植物对重金属的耐性机制及其影响因素仍然没有得到全面揭示。红树植物受到海水的周期性浸淹，海水中的主要元素Ca对其影响重大。已有研究证明Ca能提高植物对重金属的耐受作用，而对于Ca在红树植物重金属耐性中的作用及其机制的研究鲜见报道。本文从学术思想上提出Ca可能是影响红树植物在高污染环境耐受重金属的重要因素之一。 本文以红树植物秋茄为研究材料，采用Hoagland营养液培养，实验采用完全随机设计设9个处理，Cd浓度为0、0.5、5.0mgL-1三个水平；Ca浓度为0、400、800mgL-1三个水平，...Currently, mangrove wetlands facing more serious heavy metal pollution, heavy metal pollution in mangrove wetlands restoration become a hot topic in recent years, however, the mechanism of heavy metal tolerance of mangrove and its influencing factors are still not fully revealed. Mangrove plants suffer periodic seawater inundation, seawater significant impact on its major elements Ca. Ca is the la...学位：理学硕士院系专业：生命科学学院_生态学学号：2162011115249

Effect of Calcium Supply on Photosynthesis and Ultrastructure of Cells of Kandelia obovata(S.L.)Yong Under Cadmium Stress

研究了不同钙(CA)浓度下,重金属镉(Cd)对红树植物秋茄[kAndElIA ObOVATA(S.l.)yOng)]毒害的差异.采用HOAglAnd营养液培养,实验采用完全随机设计设9个处理,Cd质量浓度为0,0.5,5.0Mg/l 3个水平;CA质量浓度为0,400,800Mg/l 3个水平,研究CA对重金属Cd胁迫下红树植物秋茄叶片光合指标、叶绿素含量、叶组织的解剖结构、叶绿体等超微结构的影响.研究表明:Cd胁迫显著降低了秋茄叶片的净光合速率、气孔导度、胞间二氧化碳浓度和蒸腾速率,同时叶绿素含量减少,说明Cd对秋茄光合系统有一定的破坏作用,施加一定外源CA,秋茄叶片光合指标显著上升,同时叶绿素含量增加,说明CA对秋茄的光合作用有很强的促进效果.施加CA在一定程度上缓解了秋茄叶片重金属胁迫形成的解剖结构的“旱生化“,然而在解剖结构层面上的变化差异不显著.CA对Cd引起的细胞器结构的损伤破坏有一定的保护和缓解作用,施加外源CA缓解Cd对细胞器结构破坏的能力也不同,其中适量的CA对Cd胁迫下的细胞核和叶绿体有很强的修复功能.研究率先揭示了CA对红树植物耐重金属方面的在光合作用和超微结构方面的表征,以期为揭示红树植物对于重金属的耐性机制及其关键影响因素,并为红树林生态系统重金属污染修复治理提供新的理论依据,为红树林污染的修复提供了一条新思路.This paper studies the effect of various Ca concentrations on Cd-stressed mangrove species(Kandelia obovata(S.L.)Yong).9cross-deals were designed completely randomly using Hoagland nutrient solution culture experiment with Cd concentration of 0,0.5,5.0mg/L and Ca concentration of 0,400,800mg/L.Photosynthetic index,chlorophyll content,and leaf tissue anatomy of chloroplast ultrastructure of mangrove plants were observed under these experimental conditions.Results showed that Cd stress significantly reduced the net photosynthetic rate,stomatal conductance,intercellular carbon dioxide concentration and transpiration rate of K.obovata.The chlorophyll content decreased under Cd stress,indicating that Cd ion had some damaging effects on K.obovata photosynthetic system.Addition of exogenous Ca ion to K.obovata significantly increased the leaf photosynthetic indexes and the chlorophyll content indicating that Ca had a strong promoting effect on the photosynthesis of K.obovata.Therefore,Ca could,to some extent,alleviate the "dry formation" of leaf anatomy of K.obovataunder the heavy metal stress,but differences in the anatomy of the change was not significant.Our data also showed that Ca ions have some protection and relief on Cd-induced cell structure damage.Our results revealed the effect of Ca on heavy metal resistance of mangrove plants in photosynthesis and ultrastructural characterization,and discovered the mechanisms of heavy metal tolerance and key control factors.Our study provides a new theoretical basis for dealing with heavy metal pollution in mangrove ecosystems and a new way to restore polluted mangroves.国家自然科学基金(30530150

Effects of Arbuscular Mycorrhizal Inoculation and Cd Stress on the Growth and Antioxidant Enzyme System of Kandelia obovata

近年来,由于工农业发展导致的河口重金属污染等的影响,红树林退化与消失的趋势相当严重,红树林的保育恢复已成为我国环境保护工作的重点.立足于丛枝菌根真菌(ArbuSCulAr MyCOrrHIzAl fungI,AMf)与红树植物的共生关系,以红树植物秋茄(kAndElIA ObOVATA(S.,l.)yOng)为试材,在施加重金属Cd(0,5,10,20,40Mg/kg)的条件下,通过接种与不接种混合AMf,对比研究从红树林生境中筛选扩繁的优势AMf菌种对秋茄幼苗生长与抗氧化酶系统的影响.研究表明:接种AMf使得秋茄幼苗的生物量增加,但株高未出现明显变化.Cd胁迫引起了秋茄叶片和根系丙二醛(MdA)含量的持续上升,且超氧化物歧化酶(SOd)、过氧化物酶(POd)、过氧化氢酶(CAT)活性表现为低含量下刺激,高含量下抑制的效应.接种AMf使得MdA含量显著减少,SOd、POd、CAT活性显著增加,从而能够更好地清除活性氧,减轻Cd胁迫下秋茄的膜脂过氧化程度,保护植物.研究揭示AMf在红树林湿地生态系统中潜在的抗重金属污染生理生态功能,为红树林污染的生物修复提供了一条新思路.In recent decades,mangroves have degenerated dramatically in China due to estuarine heavy metal pollution resulting from industrial and agricultural development.As a result,mangrove conservation and restoration have become the priority of environmental protection.Based on the symbiotic relationships of AMF and mangrove plant,the effect of AMF on the growth and antioxidant enzyme system of Kandelia obovata(S.,L.) Yong under cadmium(Cd) stress(0,5,10,20,40 mg/kg) was studied,with or without the inoculation of four dominant AMF species selected from mangrove habitat as the mixed inocula.The results showed that AMF inoculation increased the biomass of K.obovata,while no variation was observed in plant height.Cd stress caused a continuous increase of malondialdehyde(MDA) content in leaves and roots of K.obovata,and the activities of superoxide dismutase(SOD),peroxidase(POD),and catalase(CAT) showed a stimulation effect under low Cd treatment strength and an inhibition effect under high Cd treatment strength.AMF inoculation significantly decreased the MDA content,meanwhile,the activities of SOD,POD,and CAT were increased,thus could scavenge more reactive oxygen species(ROS),alleviate the degree of membrane lipid peroxidation,and protect the plant cells.This research disclosed the potential function of AMF in mangrove plant against heavy metal stress for the first time,and provided a new method of mangrove pollution bioremediation.国家自然科学基金项目(31170471;30970527

Preliminary Study of SPEEK Membranes for Direct Methanol Fuel Cells Application

　应用电化学方法研究了SPEEK膜的甲醇渗透性能.SPEEK膜具有比Nafion115膜低的甲醇渗透.以其作质子交换膜电解质组装的直接甲醇燃料电池(DMFCs)开路电压高于Nafion115膜组装的DMFC开路电压,但电池的放电性能尚待改进.本研究可为SPEEK应用于直接甲醇燃料电池提供一定的依据.This paper describes the methanol permeability characterization of SPEEK membranes and their feasibility for DMFC application. The SPEEK membranes showed a significant lower methanol permeation than Nafion~115 determined from voltammetric methods. An increase in open circuit voltage was found in the performance of SPEEK membranes in DMFC. The power density of the cell using SPEEK membrane was considerably poorer than that of Nafion~115. If modified properly, the SPEEK membranes can be chosen for DMFC application based on this study.作者联系地址：中国科学院大连化学物理研究所直接醇类燃料电池实验室,中国科学院大连化学物理研究所直接醇类燃料电池实验室,中国科学院大连化学物理研究所直接醇类燃料电池实验室,中国科学院大连化学物理研究所直接醇类燃料电池实验室,中国科学院大连化学物理研究所直接醇类燃料电池实验室,大连理工大学等离子体物理化学实验室 辽宁大连116023大连理工大学等离子体物理化学实验室辽宁大连116023 ,辽宁大连116023 ,辽宁大连116023 ,辽宁大连116023 ,辽宁大连116023 ,辽宁大连116023Author's Address: 1,2, LIANG Zhen-xing~1, ZHAO Xin-sheng~1, XIN Qin~1, SUN Gong-quan~1, YANG Xue-feng~2 1.Direct Alcohol Fuel Cells Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023,China, 2. Laboratory of Plasma Physical Chemistry,Dalian University of Technology,Dalian 116023,Chin