盐胁迫对欧李幼苗生理响应及离子含量的影响

为给开发和选育耐盐植物资源提供科学依据,以温室内盆栽1年生欧李幼苗为试材,研究欧李在盐胁迫下其抗氧化酶、呼吸参数及离子含量的变化,探究欧李对盐处理的耐受性。结果表明:盐胁迫下,欧李植株根部抗氧化酶活性、MDA含量和电解质渗透率均随时间的延长呈上升趋势;总呼吸速率随处理时间的延长而增强,而交替呼吸(alternative,Alt)和细胞色素(cytochrome,Cyt)呼吸出现拮抗效应,交替呼吸比率上升,细胞色素途径呼吸下降。欧李根部和叶片K+含量随处理时间的延长而降低,Na+含量逐渐积累;根部Ca2+含量没有显著变化,但叶片中含量下降;根部Mg2+含量呈下降趋势,叶片中含量上升;Zn2+和Cu2+含量在叶组织中均无显著变化,根部中含量略微升高。根部和叶片中K+/Na+随盐胁迫时间的延长而降低,说明根部对K+的吸收受到了盐胁迫的影响。     

干旱胁迫和复水后台湾相思、银合欢和火棘幼苗的生理变化

以台湾相思、银合欢和火棘幼苗为试验材料,人工模拟干旱胁迫环境,通过测定各树种幼苗叶片的生理指标,研究了干旱胁迫对这3种幼苗的影响,并用主成分法综合评定了各树种的抗旱性。结果表明,干旱胁迫期间3种幼苗的叶片组织含水量下降,复水处理后恢复到与对照相近水平;3种幼苗叶片的叶绿素含量上升,复水后下降;3种幼苗叶片的脯氨酸、可溶性蛋白、可溶性糖含量上升或上升后下降,复水后一般恢复到对照水平;台湾相思和火棘幼苗的叶片SOD活性显著上升后小幅波动,而银合欢的幼苗叶片SOD活性持续增加;台湾相思和火棘幼苗的叶片丙二醛含量逐渐上升,银合欢上升后波动。3种幼苗叶片的SOD活性和丙二醛含量复水后均下降。对生理指标进行主成分分析表明,3种幼苗的抗旱性为台湾相思>银合欢>火棘。     

干旱胁迫对‘菊花桃’幼苗生长及生理特性的影响

【目的】探究‘菊花桃’的抗旱性,为观赏桃新品种的选育提供参考依据。【方法】以观赏桃品种‘菊花桃’1年生嫁接苗为研究对象,采用盆栽控水的方法,分别设置对照、轻度干旱胁迫、中度干旱胁迫和重度干旱胁迫4个处理组进行试验,研究在不同干旱胁迫处理下‘菊花桃’幼苗生长及生理特性受到的影响。【结果】轻度干旱胁迫下,‘菊花桃’幼苗与对照相比受到了较轻的伤害,少部分叶片出现萎蔫;中度胁迫处理下,‘菊花桃’幼苗约1/2的叶片萎蔫卷曲,叶尖和叶缘泛黄,且叶片有少量白色斑点;重度胁迫处理下,‘菊花桃’幼苗大部分叶片卷曲、枯黄,且伴有叶片掉落,同时叶片有大量白色斑点。随干旱胁迫时长的增加,叶片相对含水量均逐渐降低,轻度、中度和重度干旱处理下均于胁迫30 d后降至最小值;光合色素含量、可溶性蛋白含量、POD活性、SOD活性均在试验初期上升,在试验中期和后期下降;丙二醛含量逐渐上升,轻度、中度和重度干旱处理下均于胁迫30 d后上升至最大值。随胁迫程度的加强,‘菊花桃’幼苗的苗高生长量、地径生长量和叶片相对含水量均逐渐降低,重度干旱胁迫下下降至最小值;丙二醛含量逐渐上升,重度干旱胁迫下上升至最大值;光合色素含量、可溶性蛋白含量、POD活性、SOD活性在试验初期上升,且重度干旱胁迫下上升幅度最大,试验中期和后期下降,重度干旱胁迫下下降幅度最大。【结论】‘菊花桃’幼苗具有较强的抗旱性。     

干旱胁迫对麻疯树幼苗抗氧化代谢的影响

采用盆栽控水的方法,研究了不同程度干旱胁迫下麻疯树幼苗叶片相对含水量（LRWC）、质膜透性、相对电导率（REC）、丙二醛（MDA）含量及抗氧化酶活性的变化。结果表明,麻疯树幼苗叶片相对含水量随胁迫时间的增加呈极显著（P〈0．01）下降趋势;相对电导率、丙二醛含量随胁迫时间的增加而呈极显著（P〈0．01）增加趋势,胁迫初期和中期二者增加幅度相对较小,胁迫后期急剧增加;超氧化物歧化酶（SOD）活性随胁迫时间的增加而持续升高,过氧化物酶（POD）活性和过氧化氢酶（CAT）活性随胁迫时间的增加呈先升高后下降的趋势,在W7（干旱35d）时POD和CAT活性达到最大值。     

干旱胁迫对马银花形态和生理指标的影响

通过盆栽控水法人工模拟土壤干旱条件,设置对照(CK)、轻度干旱胁迫(LS)、中度干旱胁迫(MS)、和重度干旱胁迫(HS)4个处理,研究不同干旱胁迫强度对马银花的形态指标和生理指标的影响。结果表明:随着干旱胁迫程度的加深和时间的延长,马银花的生长发育受到抑制,叶片的萎蔫干枯现象越来越明显;叶片相对含水量缓慢降低,而电解质渗透率和丙二醛含量均逐渐升高,细胞膜发生过氧化作用而受损;有机渗透调节物质(包括可溶性糖和可溶性蛋白)大量积累;细胞内抗氧化酶(POD、CAT、SOD)活性均呈先增加后降低的变化趋势,但长时间的干旱胁迫会抑制SOD、POD和CAT活性。该研究表明马银花有一定的抗旱性,能够忍耐中度干旱胁迫(田间持水量的40%～45%)。     

高温胁迫对刺槐幼苗生理指标的影响

以刺槐实验材料,研究模拟干旱胁迫对其叶片POD活性、丙二醛含量和脯氨酸含量的影响。结果表明:在模拟干旱胁迫条件下,叶片POD活性较之对照组均出现了上升,其中高温胁迫(40℃)的POD活性上升最为显著;叶片丙二醛和脯氨酸的含量变化相似,均较之对照组出现了不同程度的上升,并且模拟干旱胁迫越严重,丙二醛和脯氨酸的含量上升的越显著。     

4种绿化幼苗对干旱胁迫的生理响应

在人工模拟干旱环境下,测定了菜豆树Radermachera sinica、铁冬青Ilex rotunda、紫楠Phoebe sheareri、锯叶竹节树Carallia diplopetela的生理指标以研究干旱胁迫的影响。结果表明:干旱胁迫处理期间,4种幼苗叶片组织含水量逐渐下降;铁冬青幼苗的叶片叶绿素含量先升后降,其余幼苗逐渐上升;紫楠幼苗的叶片可溶性糖含量先升后降,其余幼苗逐渐上升;菜豆树幼苗的叶片蛋白质含量逐渐上升,铁冬青幼苗的叶片蛋白质含量呈波动上升的趋势,紫楠幼苗显著增加后保持稳定,锯叶竹节树幼苗无显著变化;菜豆树和锯叶竹节树幼苗的叶片脯氨酸含量逐渐上升,铁冬青幼苗逐渐下降,紫楠幼苗波动性上升;菜豆树和锯叶竹节树幼苗叶片的超氧化物歧化酶活性持续下降,铁冬青先降后升,而紫楠先升后降。4种幼苗叶片的丙二醛含量均不断上升。主成分分析表明,4种幼苗的抗旱能力为铁冬青锯叶竹节树紫楠菜豆树。     

外源水杨酸对盐胁迫下白榆生理特性的影响

目的]以白榆幼苗为材料,研究不同浓度水杨酸(SA)的喷施对盐胁迫下白榆生理代谢的影响。[方法]以1年生白榆品种‘白洼一号’幼苗为材料,在0、50、100和150 mmol·L~(-1)Na Cl浓度下,喷施不同浓度SA(0、0.5、1.0、2.0 mmol·L~(-1)),处理30 d后对白榆水分生理、膜脂过氧化、光合色素含量和光合气体交换参数进行测定。[结果]表明:(1)盐胁迫下,外源SA可以显著提高白榆叶片相对含水量、可溶性糖含量,并降低丙二醛含量,但对电解质渗透率影响不显著。(2)0.5和2.0 mmol·L~(-1)SA会显著提高50和100 mmol·L~(-1)Na Cl胁迫下白榆叶片的光合色素含量,1.0 mmol·L~(-1)SA对各盐浓度下光合色素含量改善作用均不明显。(3)2.0 mmol·L~(-1)SA的添加提高了盐胁迫下白榆光合气体交换参数,1.0 mmol·L~(-1)SA明显降低了50 mmol·L~(-1)盐浓度下白榆叶片的净光合速率和气孔导度。[结论]适宜浓度的SA能改善白榆的生理参数,隶属函数法综合评价表明:0.5和2.0 mmol·L~(-1)SA对盐胁迫下白榆生理参数的改善作用较明显。     

外源硼酸钠对桂花幼苗抗寒性的影响

采用人工气候室模拟低温环境,研究不同浓度的外源硼酸钠对桂花幼苗抗寒性的影响。结果显示:在4℃低温胁迫下,随时间的延长,外源硼酸钠处理桂花叶片MDA含量和可溶性蛋白含量逐渐升高,游离脯氨酸、可溶性糖含量以及SOD、CAT酶活性变化趋势为先上升后下降,POD活性持续上升;外喷0.5%~1%浓度的硼酸钠可显著减少桂花叶片MDA含量,增加游离脯氨酸,促进可溶性蛋白和可溶性糖的积累,提高SOD、POD、CAT抗氧化酶活性;0.5%浓度的硼酸钠可促进植株纵向生长,1%~2%浓度的硼酸钠对低温胁迫下桂花幼苗纵向生长产生一定的抑制作用,且浓度越高抑制性越强。低温胁迫对桂花幼苗产生一定程度的伤害,适当浓度外源硼酸钠处理可以有效缓解低温胁迫对桂花叶片的伤害,提高桂花幼苗的抗寒性。     

土壤含水量对凤丹幼苗根颈加粗和生理特性影响

在盆栽条件下研究了土壤相时含水量(SRWC)对凤丹幼苗根颈加粗和部分生理特性的影响.试验共设5个水分水平(土壤相对含水量分别为100%(CK)、75%～80%、65%～70%、55%～60%、45%～50%,处理时间为20 d.结果表明:与CK相比,适度的水分胁迫(土壤相对含水量为75%～80%)下,凤丹幼苗的叶面积、主根长显著增大,根颈粗增大了17.95%,脯氨酸含量增加近一倍,根系活力增大了12.57%,MDA含量减少了27.91%.说明适度的水分胁迫有利于凤丹生长发育及根颈加粗.除此之外,随着土壤相对含水量的降低,凤丹幼苗的主根长、根颈粗、叶面积、地上部及地下部干鲜重等指标呈下降趋势;叶绿素、可溶性糖含量下降,叶片游离脯氨酸和丙二醛含量上升.     

盐旱交叉胁迫对皂角幼苗保护酶活性的影响

以一年生皂角Gleditsia sinensis Lam.实生苗为材料,研究干旱和盐分交叉胁迫对其膜质过氧化和保护酶活性的影响.结果表明:盐旱交叉胁迫下,丙二醛(MDA)含量、膜透性呈上升趋势,超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性先上升后下降;在相同的处理下,随着处理时间的延长,膜透性和MDA含量呈上升趋势,SOD、POD活性均下降,CAT活性先上升后下降.分析认为皂角幼苗在盐旱交叉胁迫下表现出交叉适应性,适度的干旱胁迫可增加皂角的抗盐能力.     

低温胁迫对蜡梅几个抗逆生理指标的影响

以3个蜡梅品种为试验材料,通过人工低温处理,对枝条相对电导率、超氧化物歧化酶（SOD）、过氧化物酶（POD）、丙二醛（MDA）等指标进行了研究,并利用Logistic方程计算了各品种的半致死温度。结果表明,3个品种的抗寒性具有明显差异,抗寒能力依次为：‘玉碗藏红’〉‘出水芙蓉’〉‘琥珀’。降温过程中,耐寒性强的品种能保持较高的SOD和POD酶活性和较低的MDA含量。因此,相对电导率、SOD、POD、MDA在一定程度上能反映蜡梅的抗寒能力,可作为其抗寒性评价指标。     

Genotypic Differences in Antioxidative Stress and Salt Tolerance of Three Poplars Under Salt Stress

To evaluate genotypic difference in antioxidative ability and salt tolerance in poplars, the authors investigated the effects of increasing content of soil NaCl on salt concentration in leaves, superoxide dismutase (SOD) and peroxidase (POD) activities, malondialdehyde (MDA) content, and membrane permeability (MP) in Populus euphratica Oliv., P. popularis “35–44,” and P. × euramericana cv. I-214 (hereafter abbreviated as P. cv. I-214). Na⁺ and Cl⁻ concentrations in leaves of P. popularis increased markedly over the increase of the duration of exposure to salinity, and culminated after 28 days of salt stress. SOD and POD activities declined correspondingly, followed by significant increases of MDA and MP, and leaf injury was finally observed. Compared with P. popularis, leaf Na⁺ and Cl⁻ in P. cv. I-214 exhibited a trend similar to P. popularis, but a lower salt-induced increase of MDA and permeability was observed and lighter leaf necrosis occurred. In contrast to P. popularis and P. cv. I-214, SOD and POD activities in P. euphratica leaves increased rapidly at the beginning of salt stress with a light soil NaCl concentration of 58.5 mmol/L. Furthermore, salt ion concentration, MDA content, and MP in P. euphratica leaves did not increase significantly during 28 days of increasing salt stress. Therefore, the increase in MP in P. popularis and P. cv. I-214 had a close relationship with a salt buildup in leaves under increasing salt stress. Salt-induced declines of SOD and POD activities might accelerate lipid peroxide and consequently resulted in ion leakage. P. euphratica rapidly activated antioxidant enzymes after the onset of salt stress, which might reduce the accumulation of reactive oxygen species and the subsequent acceleration of lipid peroxide. P. euphratica leaves exhibited a higher capacity to exclude salt in a longer period of increasing salinity, thus limited salt-induced lipid peroxide and MP, which contributed to membrane integrity maintenance and salt tolerance of P. euphratica. Translated from Journal of Beijing Forestry University, 2005, 27(3) (in Chinese)     

俄罗斯桃叶卫矛组织培养苗对盐胁迫的生理响应

采用盆栽方法,以俄罗斯桃叶卫矛组织培养苗为材料,用不同浓度(0,40,80,120mmol/L)的NaCl溶液进行处理,对盐胁迫下俄罗斯桃叶卫矛的形态表现和叶绿素含量、膜透性、丙二醛(MDA)、超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性等生理指标进行研究。结果表明:在盐胁迫下植物的株高生长量逐渐受到抑制;叶绿素含量随盐浓度的增加呈现下降趋势;膜透性、MDA、SOD、POD活性均随盐浓度增加而增加;40—80mmol/L的NaCl低浓度溶液胁迫后促进了俄罗斯桃叶卫矛根冠比的增加,而高浓度(120mmol/L)NaCl溶液抑制了根冠比的增加。进一步酶活指标分析表明,在盐胁迫下,植株的叶片质膜结构受到一定的伤害,但MDA含量差异不明显,而SOD和POD活性随着盐浓度升高显著上升。研究认为,俄罗斯桃叶卫矛通过提高植株的抗氧化能力来抵抗盐胁迫造成的伤害,对盐胁迫具有较强的适应能力。     

NaCl胁迫对构树组培苗抗氧化酶活性及同工酶谱的影响(英文)

构树组培苗在50,75,100,125和150 mmol-L-1 NaCl胁迫下,SOD,POD,CAT活性和这3种抗氧化酶同工酶谱的变化情况,以及不同浓度NaCI对可溶性蛋白、脯氨酸和MDA含量的影响.结果表明:NaCI浓度小于100mmol.L-1时可溶蛋白含量升高,随着NaCl浓度的增加可溶蛋白含量降低.低浓度NaCl使SOD活性略有降低,随着浓度升高活性逐渐增强;SOD同工酶谱在NaCI胁迫后变化明显.POD活性变化趋势与SOD相似,而POD同工酶谱略有变化.CAT活性明显提高,而其同工酶谱变化甚微.此外,NaCl胁迫还导致脯氨酸含量明显升高,而MDA含量呈现先升高后降低的趋势.     

两种润楠属植物耐盐性研究

用0%、0.1%、0.2%、0.3%NaCl溶液共4个水平对浙江润楠（Machilus chekiangensis）和薄叶润楠（M.leptophylla）进行盐处理,研究结果表明：在轻度（0.1%～0.2%）盐分胁迫下,浙江润楠苗木没有表现出明显的受害迹象,而薄叶润楠在0.1%的盐分胁迫下一段时间就表现出较明显的受害迹象。随着盐胁迫浓度的增加和胁迫时间的延长,两种苗木出现胁迫症状的时间缩短,苗高增长和地径增长均呈下降趋势,细胞膜透性、丙二醛含量（MDA）、脯氨酸含量、可溶性糖含量呈上升趋势,Fv/Fm呈下降趋势。试验结果可知,浙江润楠能在盐碱量中等（不大于0.2%）的土地上正常生长,表现出较强的抗盐能力;相对于浙江润楠而言,薄叶润楠的抗盐性则较差。     

干旱胁迫对白桦实生苗保护酶活性及脂质过氧化作用的影响

目前 ,活性氧自由基与植物抗逆性关系的研究正在日益深入 (戴金平等 ,1 991 ;王以柔等 ,1 995 ;许长城等 ,1 993;Ｊｏｈｎ ,1 992 ;Ｍａｒｃｅｌａｅｔａｌ.,1 993;阎秀峰等 ,1 999) ,对水分亏缺下活性氧对植物的氧化伤害及植物防御系统的反应也作了大量的研究 (陈立松等 ,1 998;1 999;沈秀瑛等 ,1 995 ;吕庆等 ,1 996;王爱国等 ,1 990 ;许长城等 ,1 993;阎秀峰等 ,1 999;Ｍｉｓｈｒａｅｔａｌ.,1 993)。在正常情况下 ,植物体内活性氧产生与清除处于平衡状态 ,不会导致细胞伤害 ,氧自由基的清除剂可分为酶促和非酶促两大类 (蒋明义等 ,1 996…     

Seasonal differences in freezing stress resistance of needles of Pinus nigra and Pinus resinosa: evaluation of the electrolyte leakage method

Seasonal changes in freezing stress resistance of needles of red pine (Pinus resinosa Ait.) and Austrian pine (Pinus nigra Arnold) trees were measured by an electrolyte leakage method and by visual observation. During most of the year, freezing stress resistance determined by the two methods gave similar results. The electrolyte leakage method provided a good estimate of seasonal changes in freezing stress resistance except for red pine needles in their most winter-hardy state. To obtain a reliable estimate of freezing stress resistance in winter-hardy red pine needles it was necessary to combine the electrolyte leakage method with visual observations. When red pine needles survived exposure to -80 degrees C or lower, electrolyte leakage was never more than 30% even when the needles were exposed to a slow freeze-thaw stress of -196 degrees C. However, rapid freezing of red pine needles to -196 degrees C resulted in electrolyte leakage of over 80%. Red pine needles attained a much higher freezing stress resistance during the winter than Austrian pine. Red pine needles also acclimated and deacclimated faster than Austrian pine needles. An index of injury was developed based on the electrolyte leakage method ((R(2) + R(1))/2, where R(1) is the minimum % electrolyte leakage from noninjured tissue and R(2) is the maximum % electrolyte leakage at the highest injury) that reliably predicted freezing stress resistance of pine needles for most of the year. Important aspects for developing a successful index of injury for pine needles are: use of cut needles, vacuum infiltration and shaking during incubation in water.We conclude that: (1) during cold acclimation the cell wall properties of the pine needles changed and these changes, which appeared to differ in the two species, might explain the very low leakage of electrolytes from winter-hardy needles of red pine; (2) pine needles survive winter by developing the ability to tolerate extracellular ice formation, because after rapid freezing the needles were severely injured; and (3) red pine is adapted to a shorter growing season and colder winters than Austrian pine.     

Effects of salt-alkali stress on active oxygen metabolism in roots of Spiraea × bumalda ’Gold Mound’ and Spiraea × bumalda ’Gold Flame’

Under artificially-simulated complex salt-alkali stress, the levels of active oxygen metabolism in roots were studied using three-year-old cutting seedlings of Spiraea × bumalda ’Gold Mound’ and Spiraea × bumalda ’Gold Flame’. The present study aimed at exploring the antioxidant capacity in roots of spiraeas and revealing their adaptability to salt-alkali stress. Results indicate that the oxygen free radicals contents, electrolyte leakage rates and MDA contents in roots of Spiraea × bumalda ’Gold Mound’ and Spiraea × bumalda ’Gold Flame’ show an increasing tendency with the increases of the salinity and pH value, whereas the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) all increased firstly and then decreased. With the increase in intensity of salt-alkali stress, the CAT activity in roots of Spiraea × bumalda ’Gold Flame’ is higher and the increasing extents in the oxygen free radicals contents, electrolyte leakage rates as well as MDA contents are lower compared with Spiraea × bumalda ’Gold Mound’, indicating that Spiraea × bumalda ’Gold Flame’ has a stronger antioxidant capacity.     

盐分胁迫对土沉香苗木生长和生理指标的影响

通过测定土沉香幼苗在盐分胁迫下生长与生理特征,探讨其耐盐性。结果表明,土沉香幼苗的苗高和地径的增长率随着盐分浓度的增加而减少;叶片膜透性、MDA摩尔浓度、SOD含量、游离脯氨酸含量随着盐分浓度的增加而增加,当NaCl质量分数≤0.4%时,叶片膜透性、MDA摩尔浓度、SOD含量、游离脯氨酸含量与对照相比增加不显著;土沉香叶片中叶绿素含量随着NaCl质量分数的增大呈先增加后减少的趋势,低浓度的盐分胁迫能使叶片中的叶绿素含量增加。由此说明,土沉香苗木具有一定的耐盐性。