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1.
通过模拟野外条件下落叶松根系增加分泌的草酸和柠檬酸数量,向落叶松苗木外源添加系列浓度有机酸溶液,研究了不同浓度草酸和柠檬酸对暗棕壤中Fe活性及落叶松幼苗吸收运输铁的影响。  相似文献   

2.
为揭示外源油菜素内酯(BR)对低温胁迫下华山松幼苗的抗寒机理,以华山松幼苗为材料,研究在低温(4℃)胁迫下,不同浓度:0mg/L(CK)、0.01mg/L(G1)、0.05mg/L(G2)、0.25mg/L(G3)、1.25mg/L(G4)的BR预处理对华山松幼苗生理特性的影响。结果表明:不同浓度的BR均可提高低温胁迫下华山松幼苗叶片的含水量和光合色素含量,提高抗氧化酶活性和渗透调节物质含量,降低丙二醛含量,且0.25mg/L的BR处理效果最佳。研究表明,外源BR能有效地缓解低温胁迫对华山松幼苗的影响,降低活性氧对其幼苗的伤害,减轻膜脂过氧化程度,提高华山松幼苗的抗寒能力。  相似文献   

3.
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。  相似文献   

4.
外源ABA对渗透胁迫下喜树幼苗生理生化指标的影响   总被引:1,自引:1,他引:0  
为给喜树栽培和利用提供理论依据,研究了外源ABA对渗透胁迫下喜树幼苗几项生理生化指标的影响。结果表明:渗透胁迫导致喜树幼苗内脯氨酸(Pro)含量增高,增施外源ABA其脯氨酸含量较渗透胁迫下低;渗透胁迫下,喜树幼苗内丙二醛(MDA)含量持续上升,外源ABA处理的喜树幼苗内丙二醛含量呈现先上升后下降的趋势;渗透胁迫使喜树幼苗的超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性持续下降,外源ABA的使用可以减缓这种下降趋势;渗透胁迫使喜树幼苗内过氧化物酶(POD)活性呈现先上升后下降的趋势,外源ABA可以提高过氧化物酶活性;渗透胁迫使喜树幼苗内喜树碱(CPT)含量上升,外源ABA处理不能显著提高喜树幼苗内喜树碱含量,而渗透胁迫导致喜树幼苗内10-羟基喜树碱(10-OH CPT)含量下降,外源ABA的使用加剧了下降趋势。  相似文献   

5.
邓恩桉幼苗根系分泌有机酸对供磷浓度的响应   总被引:1,自引:0,他引:1  
通过研究不同磷浓度对邓恩桉幼苗有机酸分泌的影响以探讨其对低磷的适应机理.试验采用Hoagland营养液并设置5个不同的磷浓度对邓恩桉幼苗进行培养,利用高效液相色谱(HPLC)测定根系分泌物中有机酸的种类及含量.结果表明:随邓恩桉幼苗生长,根际总体pH值呈现下降趋势,磷浓度不同下降幅度存在差异,无磷、极低磷和低磷条件下pH下降幅度最高.邓恩桉幼苗根系分泌物中所检测到的有机酸有草酸、甲酸、乙酸、苹果酸、乳酸和柠檬酸,其中草酸含量最高,磷浓度的不同对有机酸分泌的种类无影响,但6种有机酸分泌的量均在低磷水平时显著高于正常磷和高磷水平.邓恩桉幼苗根系分泌物对Al-P和Ca-P的活化能力高于对Fe-P的活化能力.根系分泌物对Fe-P的活化量不受磷浓度不同的影响,但对A1-P和Ca-P的活化能力不同,低磷环境下的根系分泌物对A1-P和Ca-P的活化量显著高于其他磷水平.邓恩桉幼苗低磷水平促进了根系6种有机酸的分泌,降低了根际周围的pH值,提高了根系分泌物对难溶磷的活化能力.  相似文献   

6.
为探究低温条件下外源水杨酸(salicylic acid, SA)对浙江楠(Phoebe chekiangensis)幼苗抗寒生理的影响,以期为浙江楠的保护、引种、栽培和开发利用提供科学依据。设置5个SA浓度(0、0.1、0.5、1.0、2.0 mmol·L-1)对浙江楠1年生容器苗进行连续3 d的叶面喷施处理,随后利用人工气候室模拟0℃低温,再进行连续7 d的低温胁迫处理,以20℃常温为对照(CK),测定相对电导率(REC)、叶绿素(Chl)含量、丙二醛(MDA)含量、过氧化物酶(POD)活性、超氧化物歧化酶(SOD)活性、可溶性蛋白(SP)含量、可溶性糖(SS)含量、脯氨酸(Pro)含量等生理指标,对浙江楠相关抗寒生理指标进行了相关性和主成分分析。结果表明,适宜浓度的外源SA可以有效缓解REC、MDA含量的上升及Chl含量的下降,促进抗氧化酶活性增加及渗透调节物质积累,减轻低温造成的胁迫伤害。主成分分析结果表明,外源SA预处理在0℃胁迫下能有效提高浙江楠幼苗的抗寒能力,其中1 mmol·L-1的SA处理具有最大缓解效应。  相似文献   

7.
化学试剂处理对麻疯树幼苗抗寒性影响   总被引:1,自引:0,他引:1  
研究了3种化学试剂处理对麻疯树幼苗低温前后抗氧化酶活性及相关生理生化指标的影响。结果表明:在低温胁迫前对麻疯树幼苗分别喷施不同浓度的NaCl、SA和PP。溶液,POD和SOD活性及相对电导率均发生变化。低温胁迫前,喷施0.1mmol/LSA和0.1mmol/LPP。溶液的麻疯树幼苗叶片POD和SOD活性均高于对照,可溶性蛋白质含量亦高于对照;低温胁迫后,两处理相对电导率和MDA值上升幅度低于对照和其他处理,且落叶时间推迟。表明对麻疯树幼苗喷施0.1mmol/LSA和0.1mmol/LPP。溶液能减缓低温胁迫下细胞膜的损伤;试验还发现,喷施NaCl溶液后植株可溶性蛋白质含量升高,不同化学试剂处理效果存在较大差异,而喷施化学试剂的抗寒效果优于对照。  相似文献   

8.
以尾巨桉无性系幼苗为材料,研究了低温胁迫对其生理生化的影响。试验结果表明,3℃低温胁迫对尾巨桉幼苗的电解质渗出率,随着胁迫持续时间的延长呈逐渐上升的趋势;叶绿素a的含量、叶绿素b的含量及叶绿素总量均随胁迫时间的延长而呈下降的趋势;SOD酶活性随胁迫时间呈先上升(1~3 d)而后下降(3~9 d);可溶性糖的含量随低温胁迫时间的延长而随之上升。  相似文献   

9.
低磷胁迫对不同种源马尾松幼苗的影响   总被引:3,自引:0,他引:3  
对不同种源马尾松在低磷胁迫下形态和生理生化方面的变化进行研究的结果表明:各种源幼苗的苗高、地径的净增量变化趋势一致,P3>P2>P4>P1。随磷浓度的降低根冠比增加,极低磷处理条件下各种源根冠比均最大。低磷逆境下,马尾松针叶MDA含量、保护酶活性(POD、SOD、CAT),以及游离脯氨酸含量均增加,这些指标的变化是马尾松适应低磷胁迫的主要生理影响机制之一。磷浓度为5~10 mg/L时,3个种源幼苗生长最佳。其中,贵州孟关种源较湖南汝城和广西古蓬种源更耐低磷胁迫。  相似文献   

10.
外源柠檬酸对铝胁迫下马尾松生理特性的影响   总被引:1,自引:0,他引:1  
【目的】研究受铝毒的马尾松幼苗施加外源柠檬酸后的一系列生长及生理特性变化,确定柠檬酸最佳缓解浓度,揭示柠檬酸缓解马尾松铝毒的生理机制,为土壤酸化地区马尾松的生长提供理论依据。【方法】以2种不同家系马尾松幼苗(耐铝型FJ5、铝敏感型GD20)为试验材料,采用水培法研究不同浓度柠檬酸对铝胁迫下马尾松幼苗株高增量、根系形态及其针叶中抗氧化酶[过氧化物酶(POD)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、抗坏血酸过氧化酶(APX)、谷胱甘肽还原酶(GR)]活性、活性氧(H_2O_2和O_2~(-·))、渗透调节物质(可溶性糖、可溶性蛋白、游离脯氨酸)和丙二醛含量的影响,并运用主成分分析法探讨外源柠檬酸缓解马尾松铝毒过程中起主导作用的生理指标。【结果】铝胁迫下2种家系马尾松幼苗根系总长、表面积、体积、直径及株高增量均降低,针叶内抗氧化酶活性增强,H_2O_2、O_2~(-·)、MDA和渗透调节物质含量均有所升高。经柠檬酸处理后,2种家系马尾松根系总长、表面积、体积、直径及株高增量均有所增加,其针叶内抗氧化酶活性增强,H_2O_2、O_2~(-·)、MDA和渗透调节物质含量均相应减少,且GD20变化幅度大于FJ5。主成分分析得出第一主成分中各指标贡献率大小为MDAH_2O_2脯氨酸GR。【结论】活性铝对马尾松幼苗生长产生一定的毒害作用;外源柠檬酸能有效缓解马尾松的铝毒作用,且对铝敏感型马尾松的缓解效果好于耐铝型。柠檬酸缓解铝毒的效果因浓度不同而存在差异,0.02 mmol·L-1的柠檬酸解毒效果最佳,当浓度大于0.08 mmol·L-1时,缓解效果受到抑制。MDA和H_2O_2可能是外源柠檬酸缓解铝毒作用的关键指标。  相似文献   

11.
东北林区森林凋落物中的有机酸分析   总被引:2,自引:0,他引:2  
落叶松(Larixolgensis)、水曲柳(Fraxinusmandshurica)、红松(Pinuskoraiensis)、白桦(Betulaplatyphylla)是东北林区主要造林树种。于2002年10月初,在东北林业大学帽儿山实验林场老爷岭和尖砬沟试验站(45?2?45?0碞,127?0?127?8碋)采集了4个树种林分的森林凋落物样品。采用气相色谱法对当年新鲜凋落物及半分解凋落物中有机酸进行了定性、定量分析。鉴定出13种有机酸,包括草酸、丙二酸、反丁烯二酸、丁二酸、顺丁烯二酸、苹果酸、柠檬酸、棕榈酸、硬脂酸、油酸、亚油酸、亚麻酸、花生酸。结果表明:对于新鲜凋落物而言,所测的7种低分子量有机酸中草酸含量最大,一般高于30mg/g;6种高级脂肪族酸中油酸或亚油酸含量最大,高于40mg/g;在半分解凋落物中,草酸含量最多,其次为亚油酸,再次为油酸;同一树种新鲜凋落物中有机酸种类和含量明显多于半分解凋落物。图5表2参10。  相似文献   

12.
Organic acid exudation from the roots of Chinese fir (Cunninghamia lanceolata) and Masson pine (Pinus massoniana) seedlings under low phosphorus stress was studied using the solution culture method. The results revealed that organic acid exudation from the roots of Chinese fir and Masson pine seedlings under low phosphorus stress increased. Compared with P3 (KH2PO4, 0.5 mmol/L), the average organic acid exudation from the root of Masson pine seedlings under P0 (KH2PO4, 0 mmol/L), P1 (KH2PO4, 0.03 mmol/L) and P2 (KH2PO4, 0.09 mmol/L) increased by 328.6%, 267.9% and 126.4% respectively. Masson pine from Zhejiang Province in China had the highest organic acid exudation. Under low phosphorus stress, the increase in organic acid exudation from the different provinces of Chinese fir and Masson pine varied. Masson pine from Zhejiang Province mainly increased oxalic acid, tartaric acid, citric acid and malic acid exudation, that from Guangxi Province mainly increased oxalic acid and tartaric acid exudation, and that from Guizhou Province, China mainly increased oxalic acid, tartaric acid and malic acid exudation. Chinese fir mainly increased oxalic acid and tartaric acid exudation. __________ Translated from Journal of Nanjing Forestry University, 2007, 31(2): 9–12 [译自: 南京林业大学学报]  相似文献   

13.
Larix olgensis A. Henry(Changbai larch) is a productive commercial species and good candidate for afforestation in northeast China. It is widely planted in lead-stressed soils which can induce oxidative damage in this plant. Increasing tolerance to lead(Pb) stress is therefore of keen interest. A greenhouse experiment was conducted to identify the biomass, physiological responses and Pb accumulation of L. olgensis seedlings to Pb stress under succinic acid(SA) application and to explore the interaction of exogenous SA applications and stress resistance. L. olgensis seedlings were planted in Pb-stressed or unstressed haplic cambisols in pots. In Pb-contaminated soils the seedlings were treated daily with concentrations of SA solutions at a rate approximately equivalent to 0, 0.04,0.2, 1.0, or 2.0 mmol kg~(-1) of soil for 10, 20, and 30 days,respectively. Pb treatment induced damage in the seedlings and led to the inhibition of biomass accumulation in roots,stems and leaves, and a rise in Pb accumulation in fine roots and leaves. Malondialdehyde(MDA) content and electrolyte leakage in leaves significantly increased while peroxidase(POD) activities, soluble protein and photosynthetic pigment contents in leaves were all reduced.Physiological toxicity was promoted with increasing Pb treatment times. When Pb-stressed seedlings were exposed to SA(especially 10.0 mmol L-1 over 20 days), the physiological responses for Pb-only were reversed and the biomass of roots, stems, and leaves dramatically increased.SA facilitated Pb uptake in fine roots and leaves but more Pb accumulated in fine roots. The results demonstrate that exogenous SA alleviates Pb-induced oxidative injuries and improves the tolerance of L. olgensis seedlings to Pb stress.  相似文献   

14.
高铝低磷对油茶生长及其根系分泌有机酸的影响   总被引:1,自引:0,他引:1  
以野生油茶和人工栽培油茶为研究对象,采用水培试验研究高铝低磷胁迫对油茶幼苗生长及其根系有机酸分泌的影响.结果 表明,在无磷(-p)情况下,铝毒对油茶幼苗的生长不利,而在铝胁迫下,磷的加入(0.2 mmol· L-1)能够显著降低铝的胁迫;无论是野生油茶还是人工栽培油茶,土壤中铝达到一定浓度,会显著降低油茶根系有机酸总量...  相似文献   

15.
Northern forests are currently experiencing increasing mean temperatures, especially during autumn and spring. Consequently, alterations in carbon sequestration, leaf biochemical quality and freezing tolerance (FT) are likely to occur. The interactive effects of elevated temperature and ozone (O(3)), the most harmful phytotoxic air pollutant, on Norway spruce (Picea abies (L.) Karst.) seedlings were studied by analysing phenology, metabolite concentrations in the needles, FT and gas exchange. Sampling was performed in September and May. The seedlings were exposed to a year-round elevated temperature (+1.3 °C), and to 1.4× ambient O(3) concentration during the growing season in the field. Elevated temperature increased the concentrations of amino acids, organic acids of the citric acid cycle and some carbohydrates, and reduced the concentrations of phenolic compounds, some organic acids of the shikimic acid pathway, sucrose, cyclitols and steroids, depending on the timing of the sampling. Although growth onset occurred earlier at elevated temperature, the temperature of 50% lethality (LT(50)) was similar in the treatments. Photosynthesis and the ratio of photosynthesis to dark respiration were reduced by elevated temperature. Elevated concentrations of O(3) reduced the total concentration of soluble sugars, and tended to reduce LT(50) of the needles in September. These results show that alterations in needle chemical quality can be expected at elevated temperatures, but the seedlings' sensitivity to autumn and spring frosts is not altered. Elevated O(3) has the potential to disturb cold hardening of Norway spruce seedlings in autumn, and to alter the water balance of the seedling through changes in stomatal conductance (g(s)), while elevated temperature is likely to reduce g(s) and consequently reduce the O(3)-flux inside the leaves.  相似文献   

16.
Analysis of organic acids in seleted forest litters of Northeast China   总被引:5,自引:0,他引:5  
Larch(Larix olgensis), Manchurian ash(Fraxinus mandshurica), Korean pine(Pinus koraiensis) and White birch(Betula platyphylla) are the major planting species in northeast China. The samples of forest litters were collected from the stands of the above 4 species in Laoyeling and Jianlagou experiment stations of Maorshan Exp. Forest Farm (45°12′–45°30′N, 127°30′–127°48′E), Northeast Forestry University, in early October 2002. Quantitative analysis and qualitative analysis were carried out on the organic acids existing in freshly fallen litters (L layer) and hemi-decomposed litters (F layer) of the four forest species by using Gas Chromatogram system. A wide variety of organic acids were identified, including oxalic, malonic, fumaric, succinic, maleic, malic, citric, C16:O, C18:O, C18:1, C18:2, C18:3 and C20:O acids. In respect of L litters of all samples, the oxalic acid content (over 30 mg/g) was the highest of the seven low-molecular-weight organic acids identified, while the content of oleic or linoleic (above 40mg/g) was found to be highest among the six high aliphatic acids identified. As to F litters, oxalic acid content was also the highest, followed by linoleic and oleic. For the same tree species or the same forest, the kinds and contents of organic acids in L litters were more abundant than that in F litters. Foundation item: This paper is supported by National Natural Science Foundation of China (30170768) Biography: SONG Jin-feng (1976-), female, doctor postgraduate, Harbin 150040, P. R. China. Responsible editor: Chai Ruihai  相似文献   

17.
根系产生的有机酸对根际土壤养分活化的影响   总被引:14,自引:0,他引:14  
本试验以采自中国东北3个地点的4种土壤,即棕色针叶林土、暗棕壤、黑土与黑钙土为材料,对根系分泌的两种有机酸及水在活化根际矿质养分方面的作用进行了模拟与比较。结果表明:有机酸能够活化养分,其程度主要取决于有机酸的数量和类型以及供试土壤的理化和生物化学性质;对于所有土壤类型,柠檬酸对Fe, Mn, Cu和Zn的活化效率明显高于苹果酸,而对于P, K, Ca 和Mg的活化效率并不是很高,有时甚至较苹果酸为低;所有元素的溶液浓度均随所加柠檬酸数量的增加而增加。图2表3参9。  相似文献   

18.
外源茉莉酸类化合物对2种落叶松针叶内单宁含量的影响   总被引:2,自引:0,他引:2  
为明确外源茉莉酸类化合物对落叶松防御物质单宁的诱导作用,利用喷雾处理和香草醛比色测定法,研究不同浓度外源茉莉酸类化合物对2年生兴安落叶松和长白落叶松的诱导作用,及对其针叶内单宁含量变化的影响。喷施茉莉酮(ZJ)、茉莉酸甲酯(MJA)和茉莉酸(JA)后,2种树体针叶内单宁含量增加或减少波动明显,诱导作用可持续10~20天。茉莉酮对兴安落叶松针叶内单宁含量变化的影响较茉莉酸甲酯和茉莉酸显著;但3种茉莉酸类化合物均明显影响长白落叶松针叶内单宁含量的变化。0.01mmol·L-1茉莉酮、茉莉酸甲酯和1mmol·L-1茉莉酸诱导兴安落叶松针叶内单宁含量明显变化;0.01mmol·L-1茉莉酸甲酯和1mmol·L-1茉莉酸对长白落叶松针叶内单宁含量变化影响显著。3种茉莉酸类化合物诱导兴安落叶松针叶内单宁含量的变化幅度高于长白落叶松。总之,喷施外源茉莉酸类化合物能够诱导落叶松针叶内单宁含量系统增加或减少,并具持效性;2种落叶松对外源茉莉酸类物质的应激反应不同,兴安落叶松的应激反应强度大于长白落叶松。  相似文献   

19.
Aluminum (Al) tolerance mechanisms in crop plants have been extensively researched, but our understanding of the physiological mechanisms underlying Al tolerance in trees is still limited. To investigate Al tolerance in eucalypts, seedlings of six species (Eucalyptus globulus Labill., Eucalyptus urophylla S.T. Blake, Eucalyptus dunnii Maiden, Eucalyptus saligna Sm., Eucalyptus cloeziana F. J. Muell. and Eucalyptus grandis w. Hill ex Maiden) and seedlings of six clones of Eucalyptus species were grown for 10 days in nutrient solutions containing Al concentrations varying from 0 to 2.5 microM (0 to 648 microM Al3+ activities). Root elongation of most species was inhibited only by high Al3+ activities. Low to intermediate Al3+ activities were beneficial to root elongation of all species and clones. Among the species tested, E. globulus and E. urophylla were more tolerant to Al toxicity, whereas E. grandis and E. cloeziana were more susceptible to Al-induced damage. Although E. globulus seedlings were tolerant to Al toxicity, they were highly sensitive to lanthanum (La), indicating that the tolerance mechanism is specific for Al. Fine roots accumulated more Al and their elongation was inhibited more than that of thick roots. In E. globulus, accumulation of Al in root tips increased linearly with increasing Al concentration in the nutrient solution. The majority of Al taken up was retained in the root system, and the small amounts of Al translocated to the shoot system were found mainly in older leaves. No more than 60% of the Al in the thick root tip was in an exchangeable form in the apoplast that could be removed by sequential citrate rinses. Gas chromatography/mass spectrometry and ion chromatography analyses indicated that root exposure to Al led to a greater than 200% increase in malic acid concentration in the root tips of all eucalypt species. The increase in malate concentration in response to Al treatment correlated with the degree of Al tolerance of the species. A small increase in citric acid concentration was also observed in all species, but there were no consistent changes in the concentrations of other organic acids in response to Al treatment. In all eucalypt species, Al treatment induced the secretion of citric and malic acid in root exudates, but no trend with respect to Al tolerance was observed. Thus, although malate and citrate exudation by roots may partially account for the overall high Al tolerance of these eucalypt species, it appears that tolerance is mainly derived from the internal detoxification of Al by complexation with malic acid.  相似文献   

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