模拟酸雨对小麦种子萌发和幼苗生长的影响

以中性溶液（pH=7.0）为对照,研究了pH值为1.0,2.0,3.0,4.0,5.0和6.0模拟酸雨对小麦种子萌发和幼苗生长的影响。结果表明,小麦种子萌发和幼苗生长各指标随着pH值的降低而降低,弱酸（pH5.0～6.0）条件下小麦种子能够正常萌发和生长,种子萌发和幼苗生长各指标与对照没有显著差异（P > 0.05）;在pH低于5.0时,小麦种子萌发和幼苗生长严重受阻,种子萌发和幼苗生长各指标均显著低于对照（P < 0.05）;pH为1.0时,小麦种子则完全失去活性;不同pH值模拟酸雨胁迫对小麦幼苗生理指标影响较大,叶绿素含量、类胡萝卜素含量、保护酶（SOD,POD,CAT）和非保护酶（PPO,PAL）活性随酸性的增强呈降低趋势,而相对电导率和丙二醛（MDA）含量呈上升趋势。综合分析认为,小麦幼苗生长比种子萌发对模拟酸雨的响应更为敏感。     

Effect of Simulated Acid Rain on Deterioration of Concrete

In the study the long-term exposure tests to simulated acid rain were performed in order to clarify the effect of acid rain on deterioration of concrete. Mortar specimens with 40 mm in width, 15 mm in thickness and 160 mm in length were used for the tests. At each time after the fixed rainfall was attained, those were tested physically and analyzed chemically. Finally total rainfall of 9000mm was given to the specimens. From the test results, it was confirmed that the eroded depth of the specimen has a good linear relation to the total rainfall under simulated acid rain with various pH. Surface erosion rates of the mortar specimens with an ordinary mix proportion under simulated acid rains with pH 3.0 and 2.5 were about 1.2 and three times larger than that under pH 5.6, respectively. It was also confirmed that flexural strength of the specimens with an ordinary mix proportion hardly changed under low pH simulated acid rain even after total rainfall of 9000mm was given.     

利用冠层和叶片水平的反射光谱研究模拟酸雨对小麦的影响

通过光谱分析技术,研究了模拟酸雨（SO-42：NO-31=5：1）对小麦产量和生理特性的影响。结果表明,模拟酸雨伤害了小麦叶片的结构和功能,降低了叶绿素含量和光合速率,从而显著降低了小麦的产量,经过pH为2的酸雨处理后的小麦产量降幅达19.1%。通过对植被指数的分析可以看出,小麦冠层叶绿素含量在开花期以后逐渐降低,而旗叶的叶绿素含量则在灌浆期以后开始下降,两者的下降幅度都随着酸雨pH的下降而增大。光合速率表现出与叶绿素含量相同的变化。另外,对小麦产量与不同生育期冠层和叶片水平的植被指数的相关分析表明,灌浆期的小麦冠层水平的NDVI、mND705和WI与酸雨处理后小麦的产量显著相关。总之,利用光谱分析技术可以快速、无损伤地监测不同酸雨处理对小麦的生长和营养状况的影响。     

Effect of Ethylenediaminetetraacetic Acid on Growth and Phytoremediative Ability of Two Wheat Varieties

Chelating agents are commonly used to enhance the phytoremediative ability of plants. The type of chelating agent applied and the selection of plant species are important factors to consider for successful phytoremediation. This study investigates the effects of four different rates (0, 2, 4, 8 mmol kg^?1) of ethylenediaminetetraacetic acid (EDTA) on lead (Pb) dissolution, plant growth, and the ability of two spring wheat varieties (Auqab-2000 and Inqalab-91) to accumulate Pb from contaminated soils in a pot study. The results indicated that the addition of EDTA to the soil significantly increased the aqueous solubility of Pb and that wheat variety Inqalab-91 was more tolerant to Pb than Auqab-2000. Application of EDTA at 8 mmol kg^?1 resulted in biomass yield, photosynthetic rate, and transpiration rate significantly lower in Auqab-2000 than in Inqalab-91. Although EDTA enhanced the uptake of Pb by both wheat varieties, Auqab-2000 accumulated significantly more Pb in the shoots than Inqalab-91. The results of the present study suggest that under the conditions used in this experiment, EDTA at the highest dose was the best amendment for enhanced phytoextraction of Pb using wheat. High concentrations of Pb were found in leachates collected from the bottom of columns treated with EDTA. Application of EDTA in the column leaching experiment increased the concentration of Pb in leachate with increasing EDTA dosage (0–8 mmol kg^?1). These results suggest that EDTA addition for enhancing soil cleanup must be designed properly to minimize the uncontrolled release of metals from soils into groundwater.     

CO2浓度增加对不同冬小麦品种后期生长与产量的影响

应用自行设计的模拟未来气候变化的半开放式CO2浓度递增大棚（CGC），研究CO2浓度递增对不同冬小麦品种后期生长状况与产量的影响。结果表明，CO2浓度递增，生物总量与经济产量均为增加；不同品种对CO2浓度递增的反应程度不同。     

模拟酸雨对碱性农田土壤酸缓冲容量的影响

采用模拟降雨设备,用改进的酸碱滴定曲线法研究了pH值分别为3.0,3.5,4.0,4.5和5.0的酸雨在降雨量达到120 mm,240 mm,360 mm和480 mm时土壤酸缓冲容量的变化情况.结果表明,酸碱滴定曲线法适用于天津碱性农田土壤,使北方碱性土壤酸缓冲容量降低的酸雨pH临界值可能在3.5左右.降雨量对土壤酸缓冲容量有明显影响,酸缓冲容量变化率K在120 mm处理时有最大值,并随降雨量增加有降低趋势.     

模拟酸雨对水稻、玉米和绿豆萌发及生长影响

通过模拟试验研究酸雨对水稻,玉米和绿豆的萌发及生长的影响,结果表明,ｐＨ２．０的模拟本雨明显降低作物的发芽率,伤害植物叶片,造成叶片细胞膜透性增加,使叶绿素含量,通过氧化氢酶和脱氢酶活性降低,ｐＨ３．０以上模拟酸雨短期内对作物无明显影响。     

模拟酸雨对稀土矿区铅污染农田的淋滤效应

[目的]针对赣南稀土矿区周边农田存在严重的重金属铅污染情况,研究该地区农田土壤中重金属铅迁移转化规律,旨在为矿区铅污染治理提供依据。[方法]采用模拟酸雨淋滤试验土柱观察重金属铅的淋出量变化,结合响应曲面分析试验结果。[结果]随时间的推移,铅淋出量呈现出快速下降和慢速下降两个阶段。随着pH值的减小,淋滤强度的上升使得铅淋出量呈现先上升后减小的情况。当外源铅浓度增加时,pH值的减小和淋滤强度的上升都会时铅淋出量增加。响应曲面软件对试验数据进行多元回归拟合,交互项中pH值与培养铅浓度较为显著。[结论]铅的污染程度与铅的析出呈正相关,酸雨pH值对污染农田中铅的析出有重要影响。     

酸雨对黄棕壤的致酸作用与对小麦幼苗膜脂过氧化水平的影响

通过模拟酸雨淋洗土壤,造成了土壤酸化和盐基流失。将小麦幼苗栽培于由酸雨致酸的土壤上,导致小麦幼苗的膜脂过氧化水平提高。其中致酸土壤对根系膜脂过氧化水平的影响大于对叶片膜脂过氧化水平的影响。     

优化栽培管理对四川丘陵旱地不同穗型小麦分蘖质量与产量形成的影响

为探究优化栽培管理对四川丘陵旱地不同穗型小麦分蘖质量与产量形成的影响,本研究于2017—2019年,以大穗型品种川麦104和多穗型品种川农16为材料,在秋闲季秸秆覆盖配施干猪粪条件下适期早播形成优化栽培管理,并以当地常规栽培管理为对照,解析优化栽培管理对小麦分蘖质量与产量形成的影响。结果表明,优化栽培管理下有效分蘖发生速率提高65.7%,发生期较常规栽培缩短1.6 d,第一、第二叶位分蘖发生率分别提高8.0和27.4个百分点,拔节时第一、第二叶位分蘖叶龄分别达到4.1和3.1;优化栽培管理提高了小麦拔节期N含量和非结构性碳水化合物(NSC)含量,开花期NSC含量也较常规栽培管理提高1.0~3.4个百分点;优化栽培管理下拔节期、开花期、成熟期干物质积累量显著增加,主茎干物质积累量分别提高39.8%、12.7%和9.9%,分蘖干物质积累量分别提高99.2%、35.3%和37.1%,且成熟期分蘖干物质占比较常规栽培管理增加6.2个百分点,收获指数由0.40增加到0.45(两品种两年均值)。通径分析表明,有效穗是限制两种穗型小麦产量提升的关键因子,优化栽培管理下川麦104有效穗增加11.0%~18.4%,增产13.5%~30.5%;川农16有效穗增加4.5%~8.7%,增产22.2%~23.7%。研究认为,秋闲季秸秆覆盖配施干猪粪条件下适期早播形成的优化栽培管理,可充分发挥系统优势,促进植株氮素吸收和光合生产,减弱主茎与分蘖的非对称竞争,促进优势分蘖成穗、增产,是适合四川丘陵旱地绿色丰产的栽培管理模式,配合大穗型小麦增产效果更佳。     

Silicon-Induced Growth and Yield Enhancement in Two Wheat Genotypes Differing in Salinity Tolerance

Silicon (Si) is known to alleviate a number of abiotic stresses in higher plants including salinity stress. Two independent experiments were conducted to evaluate the role of Si in alleviating salinity stress in two contrasting wheat (Triticum aestivum L.) genotypes, Auqab-2000' (salt sensitive) and SARC-3 (salt tolerant). In the first experiment, genotypes were grown in hydroponics with two levels of salinity (0 and 60 mM NaCl) with and without 2 mM Si in a completely randomized design with four replications. Salinity stress significantly (P < 0.01) decreased all of the growth parameters, increased sodium (Na⁺) concentration, and decreased potassium (K⁺) concentration in shoots of both genotypes grown in hydroponics. Silicon significantly improved growth of both genotypes. The increase in growth was more prominent under salt stress (75%) than under normal condition (15%). In the second experiment, both genotypes were grown in normal [electrical conductivity (EC) = 1.23 d Sm^–1] and natural saline field (EC = 11.92 d Sm^–1) conditions with three levels of Si (0, 75, and 150 g g^–1 Si) with three replications in a randomized complete block design. Silicon significantly (P < 0.05) decreased growth reduction in both genotypes caused by salinity stress. The grain yield under salt stress decreased from 62% to 33% and from 44% to 20% of the maximum potential in Auqab-2000 and SARC-3, respectively, when 150 g g^–1 Si was used. Auqab-2000 performed better in normal field conditions, but SARC-3 produced more straw and grain yield in saline field conditions. Addition of Si significantly (P < 0.05) improved K uptake and reduced Na⁺ uptake in both of wheat genotypes and increased the K⁺/Na⁺ ratio in shoot. Enhanced salinity tolerance and improved growth in wheat by Si application was attributed to decreased Na⁺ uptake, its restricted translocation toward shoots, and enhanced K⁺ uptake.     

模拟酸雨对盆栽马尾松叶片光合特性的影响

采用LI-6400XT便携式光合测定仪,对缙云山马尾松在不同强度酸雨(pH 5.6,pH 5.0,pH 4.0,pH3.5,pH 3.0,pH 2.5和pH 2.0)下的光合特性进行测定。结果表明:pH 3.5～5.6的酸雨处理条件下,净光合速率、蒸腾速率和气孔导度受酸雨影响不明显,从pH 3.0或pH 2.5开始出现明显的降低趋势,且pH2.0出现不同于前几种处理的日变化趋势;从水分利用效率分析,酸雨胁迫对其影响不明显;pH 4.0～5.6的酸雨处理条件下,最大净光合速率、光饱和点和光补偿点变化不明显,从pH 3.5开始出现显著降低的趋势,且在pH 2.0时受酸雨影响已经非常明显,无法模拟出最大净光合速率、光饱和点和光补偿点;总体分析,酸雨对马尾松叶片光合特性的影响临界范围为pH 3.5～4.0,酸雨对马尾松幼苗致命的影响临界范围为pH 2.0～2.5。     

模拟酸雨对芒果生长及土壤的影响

模拟酸雨田间试验结果表明，ｐＨ２．５酸雨处理有明显抑制供试桂香芒秋梢的生长，降低叶绿素含量，加速叶片中的钙、镁、铁、锰、铜、铝等元素淋洗的趋势，同时也能促使供试土壤中钙、镁盐基离子的流失，从而导致土壤ｐＨ值下降，促使锰、锌、铜等重金属微量元素及铝的活化，既阻碍了根系对锌、铁、锰３元素的吸收，又影响根对钙、镁、铜、铝４元素向地上部输送。     

模拟酸雨和镍复合污染红壤中莴笋的生长与抗氧化反应

采用盆栽实验,研究了在模拟酸雨、镍单一或复合污染的红壤中,莴笋的生长和叶片中抗氧化酶活性、活性氧和丙二醛含量的变化。结果表明,单一酸雨污染或酸雨与25 mg/kg镍的复合污染对植株生长无明显影响;酸雨增强了50-100 mg/kg镍对莴笋生长的抑制效应。复合污染下,酸雨为pH4.5时,莴笋叶片超氧化物歧化酶（SOD）、过氧化氢酶（CAT）的总体活性较单一镍污染高,而酸雨为pH3.5时则两者活性降低。复合污染下,叶片过氧化物酶（POD）活性升高,抗坏血酸过氧化物酶（APX）活性降低,且随酸雨pH降低,变化的幅度增大;同时,O2^＊ˉ的产生加快,H2O2和MDA含量升高,表明叶片组织遭受了氧化胁迫和膜脂过氧化损伤,这可能是复合污染下莴笋生长受阻的重要原因。     

Simulated Acid Rain Leaching Characteristics of Acid Soil Amended with Bio-Briquette Combustion Ash

In Chongqing City, the rapid growth of the economy has accompanied an increase of sulfur dioxide emissions from coal combustion, bringing about an expansion of acid rain affected areas and acidification of soil. Recently, we reported that coal-biomass briquettes so-called bio-briquettes (BB), which are produced from pulverized raw coal, biomass, and a sulfur fixation agent (Ca (OH)₂) under 3 to 5 tons cm^?2 pressure, have high sulfur-fixation efficiency. The BB ash contains nutritive substances such as Ca and Mg, and has a large acid-neutralizing capacity. Thus, in order to improve the acid soil in the Chongqing area, we analyzed the chemical composition of the original acid soil and the ash-amended soil, and investigated their leaching characteristics under simulated acid rain (SAR). It was found that plants and crops in Chongqing area would be injured if the present acid rain continues. We carried out a SAR leaching experiment and studeid the potential toxic effects of leachate from soil containing added ash. The results indicated that the contents of most toxic elements, with the sole exception of chromium, were below the environment standard for irrigation water. Because the BB ash was highly alkaline, the leaching aluminum (Al) species would be hydroxide rather than free Al³⁺ ion.     

模拟酸雨和Pb复合污染对羽叶鬼针草的生理特性的影响

通过盆栽试验研究了模拟酸雨(pH分别为3.5,4.5,5.6)和Pb(0～2 000 mg/kg)复合污染对羽叶鬼针草的生理特性的影响.结果表明,随着酸雨酸度的增强和Pb处理浓度的增加.羽叶鬼针草生物量和叶绿索含量均有不同程度的下降,叶和根中的丙二醛含量上升,超氧化物歧化酶和过氧化物酶活性则是先升后降,脯氨酸含量随着Pb含量和酸雨强度的增加而升高,羽叶鬼针草对酸雨有较好的耐受能力,酸雨和Pb复合污染比单一污染对羽叶鬼针草造成的胁迫更严重.     

Effects of Simulated Acid Rain on the Antioxidative System in Cinnamomum philippinense Seedlings

This study examined the importance of the antioxidative defense mechanism during the application of simulated acid rain (SAR) pH 4, pH 3, pH 2, and pH 6 as control treatment in Cinnamomum philippinense seedlings. Analysis was carried out on 1, 10, and 15 days of spraying SAR. In our results, catalase (CAT), ascorbate peroxidase (APx), guaiacol peroxidase (GPOD), and glutathione reductase (GR) activity significantly were induced on 1 day of spraying SAR pH 3 and pH 2, suggesting that C. philippinense seedlings exposed to pH 3 and pH 2 acid rain for only 1 day were under oxidative stress, and antioxidant enzyme were apparently increased until 10 days of spraying SAR pH 4. However, on 10 days of spraying SAR pH 2, the accumulated intensity of acidity significantly inhibited the activities of CAT and APx accompanying with increased concentrations of malonydialdehyde (MDA). On the contrary, GPOD activity and the ascorbic acid ratio were remarkably increased when spraying SAR pH 2 for 15 days. Therefore, GPOD and ascorbate contribute to the scavenging of ROS at stronger acidity stresses. However, they were not enough to avoid cellular damage, since membrane lipids were injured, and necrosis appeared.     

酸雨与稀土镧对大豆幼苗光合光反应复合影响的时间效应研究

采用水培法研究酸雨（AR）与稀土镧（La）对大豆幼苗叶片光合光反应复合影响的时间效应,旨在探究复合污染因子对植物自修复过程的影响。结果表明,较之不同pH值AR（pH3.0、4.0）和不同剂量La（60、300mg·L-1）的单一作用,复合处理对大豆幼苗光合光反应活性抑制程度较大,延缓各参数恢复进程（恢复拐点滞后）,恢复程度较小,明显影响了植物的自修复能力。净光合速率Pn与各光合参数相关性分析结果显示：复合处理组的植物在修复过程中,Pn变化主要受Chl、Hill反应活性的影响,Mg2＋-ATPase活性对Pn的制约最小,且随着时间的推移,AR与La复合处理组各光合参数的恢复进程不同步,自修复能力受胁迫强度和胁迫方式的影响。     

模拟酸雨对不同园林植物叶片生理生态特性的影响

采用盆栽方法,以自来水（pH值6.5）作为对照,研究了pH值为1.7,3.0,4.3,5.6模拟酸雨条件下新梢增长量、叶片损伤程度和叶片生理生态特性,并分析了园林植物对酸雨污染的敏感性反应。结果表明:不同pH值的酸雨对园林植物新叶片有不同程度的抑制,酸雨的酸度越大,对园林植物叶片的伤害越大,以pH值1.7的模拟酸雨对园林植物叶片的伤害最为严重,pH值5.6伤害较为轻微,但不同种类之间对酸雨的抗性有明显差异;pH值4.3~5.6处理对园林植物新梢生长率没有显著的影响和抑制作用,而pH值小于3.0处理则严重抑制了园林植物新梢生长;随模拟酸雨强度的增强,园林植物叶片的细胞质膜透性和丙二醛（MDA）含量逐渐升高,当pH值小于3.0时,细胞质膜透性和丙二醛（MDA）含量则急剧增加,当pH值为1.7时,不同园林植物叶片则严重受损;园林植物叶片叶绿素含量、叶片N和P含量随酸雨强度的增加逐渐降低,当pH值小于3.0时,园林植物叶片叶绿素含量、叶片N和P含量则急剧降低,当pH值为1.7时,不同园林植物叶片则严重受损;相关分析表明,酸雨增加了园林植物对环境的敏感性。园林植物对酸雨具有较强的抵抗能力,对园林植物生理活动影响的阈值pH值大致介于3.0~4.3,因此,本研究的6种园林植物可以作为酸雨灾害严重地区园林绿化及植被构建的物种。