Cd、Zn污染对玉米的毒害效应

采用均匀设计，研究土壤Cd、Zn污染对玉米的毒害效应。结果表明：玉米生物量随Cd、Zn投加量的增加而下降,在Cd的投加量为4mg／kg至20mg／kg,Zn的投加量为200～1000mg／kg的范围内，其下降量之和大于Cd～Zn复合污染造成的下降量。这表明在Cd和Zn投加范围内。Cd、Zn对玉米的毒害存在拮抗作用。     

镉毒害对小麦生理生态效应的研究进展

镉是植物生长的非必须元素,它具有很大的生物毒性,与其它重金属相比,更易被植物吸收积累,即使生长在非污染土壤上的小麦,籽粒中镉含量都在0.002~0.207 mg/kg。在参考大量文献资料的基础上,综述了镉（Cd）毒害对小麦植株幼苗的萌发、生长及小麦生理生化特性的反应,提出了小麦镉毒害影响因素与防治途径。     

锌对汞毒害小麦幼苗生长及生理活性的影响

采用学人培养法研究了汞对小麦幼苗的影响以及锌对汞毒害的缓解效应。结果表明,随着汞浓度的增加,细胞膜透性增大,MDA积累增加,SOD和POD活性上升,幼苗生长受到抑制,且与汞毒害呈正相关。当在汞胁迫溶液中加入10^-3mol/L的Zn^2 ,能使汞毒害引起的生理生化变化得以没程度的恢复,但随汞浓度的升高,锌的这种缓解效应逐渐减弱。     

椪柑叶片硼毒害症状及光合生理响应研究

  【目的】  准确及时诊断硼毒害,了解硼毒害对叶片造成的生理影响,为硼毒害的有效防治提供理论依据。  【方法】  通过田间调查和叶片养分含量测定,明确福建省安溪县椪柑叶片黄化和脱落是由硼中毒引起的。分别采集不同程度硼毒害椪柑叶片,测定叶片光合作用速率、叶绿素荧光特性和细胞膜透性。  【结果】  在正常、中度黄化和重度黄化叶片中,钾、镁、锌含量均处于椪柑适宜范围内,而中度黄化和重度黄化叶片的硼含量比正常叶片分别提高了11.11和19.71倍,显示硼毒害是造成椪柑叶片黄化的原因。椪柑叶片硼毒害症状有两种表现形式:一是症状由叶尖沿主脉向下发展,叶肉和叶脉均褪绿黄化,黄化部位可见棕褐色的坏死斑点;二是症状由叶缘向主脉发展,主脉保持绿色,叶片呈不规则的黄、绿斑驳黄化。硼毒害椪柑叶片的光合色素含量、有效光化学效率 (Fv'/Fm')、电子传递效率 (ETR)、有效量子产额 (ΦPS II) 和光化学淬灭系数 (qP) 随症状的加重而下降,而非光化学淬灭系数 (NPQ)、过剩激发能 (E) 和天线热耗散 (D) 则随症状的加重而提高,引起光合作用速率、淀粉和可溶性糖含量下降,硼毒胁迫下椪柑叶片细胞膜透性明显提高。  【结论】  过量喷施硼肥所造成的硼毒害会导致椪柑叶片黄化、异常落叶,硼毒害使椪柑光合作用受抑、光合产物合成受阻,细胞膜受到伤害。柑橘生产上应重视含硼叶面肥的合理使用,以免造成硼中毒现象。有关椪柑硼毒害的防治措施还有待进一步研究。     

向日葵对土壤中铜的积累作用研究

温室内不同Cu浓度添加土壤的向日葵盆栽试验表明,向日葵植株的部分生物学性状如地上部干物质量、地下部干物质量、最大单叶面积随土壤中Cu浓度的增加而降低,土壤中添加20mg/kgCu对向日葵根部生长抑制作用最大,而植物高度在添加100mg/kgCu浓度时最高。且不同Cu浓度处理下向日葵对Cu的积累能力不同,但植物各部分Cu含量均随土壤中添加Cu浓度的增加而增加,但在100mg/kgCu浓度处理下,向日葵对Cu的积累主要集中在根部,地上部分Cu含量很低,在200mg/kgCu浓度处理下,向日葵叶中Cu含量超过根部,达857±297mg/kg干重,Cu积累的叶根比达1.27,说明当土壤Cu浓度较高时,Cu在向日葵地上部有较高的Cu积累,集中收获植株地上部分,可移出土壤中的过多有效铜,但生长受到抑制。使用向日葵修复高浓度Cu污染土壤时,还需考虑采用其他手段接种根际微生物、转基因、设施农业环境工程技术等来增加其生物产量。     

肉桂酸对豇豆根系毒害作用的研究

为探究豇豆主要根系分泌物肉桂酸对豇豆根系的毒害作用,本研究以2种抗性差异品种豇豆特早30号(TZ30)和紫秋豇6号(ZQJ6)为试验材料,在水培条件下,施用0.2 mmol·L^-1肉桂酸,测定并分析根系的生理生化指标。结果表明,肉桂酸处理对2种豇豆根系均有明显毒害作用,2种豇豆的总根长、总根表面积、总根体积、总根尖数均显著下降,但TZ30比ZQJ6降幅小,具有较高抗性。TZ30的平均根系直径升高,无显著性差异;ZQJ6的平均根系直径升高,呈显著性差异,表明TZ30的抗性较高,并说明肉桂酸对豇豆根系的影响主要在幼嫩根系部位。2种豇豆根系的超氧化物歧化酶(SOD)、过氧化物酶(POD)和抗坏血酸过氧化物酶(APX)活性均显著升高,说明豇豆可以通过提高抗氧化酶的活性来抵抗肉桂酸的自毒作用,其中TZ30的3种抗氧化酶活性提高程度均高于ZQJ6,说明TZ30对肉桂酸的抗性强于ZQJ6。2种豇豆的根系相对电导率均显著增加,根系可溶性蛋白含量均显著下降,说明肉桂酸破坏了豇豆根系的细胞结构,其中TZ30的根系相对电导率增加程度和可溶性蛋白下降程度均较ZQJ6高,说明TZ30的细胞...     

不同铜水平下海洲香薷的生理特性和铜积累研究

本文研究了Cu对耐性植物海洲香薷(Elsholtzia splendens)的生长、Cu积累、叶绿素含量和根系活力的影响,探讨了后2项生理指标与海洲香薷Cu积累之间的关系。研究结果表明:1) 低浓度Cu可促进海洲香薷生长(0.31～50 mmol/L),但随着其浓度的增加出现抑制现象(75～100 mmol/L)。2)叶绿素a及叶绿素b受Cu的影响规律一致。100 mmol/L的高Cu处理可显著降低这两者含量,其余Cu处理水平没有产生显著影响。3)随着Cu浓度的增加根系活力呈现不断下降的趋势。与其余处理相比,Cu浓度高于75 mmol/L时影响达显著水平。4) 地上部和根系Cu浓度、积累量均随着Cu处理浓度的增加而增加,但地上部分Cu积累水平未达到超积累植物的要求。     

灰钙土重金属污染对农作物生理生化作用的影响

向灰钙土中加入不同量的Ｐｂ、Ｃｄ、Ａｓ、Ｃｕ，对小麦玉米进行两年的盆栽试验，结果表明对作物生理生化作用的影响明显。除Ｐｂ对玉米叶绿素含量影响相关不显外，其余均对小麦、玉米危害较大，呈负相关性。Ｐｂ、Ｃｄ、Ａｓ、Ｃｕ对茎叶中过氧化氢酶活性无明显影响，但Ａｓ、Ｃｕ、Ｃｄ对根系中过氧化氢酶有明显的抑制作用。四种元素对茎叶中的蔗糖酶亦有明显影响。并且叶绿素含量降至对照的８０－９０％时土壤重金属浓度与农作     

农田土壤铜污染评价和油菜铜积累特征研究

以湖北省大冶市农田土壤和油菜为研究对象,调查了10个区域40个农田土壤样品的Cu污染状况,采用单项污染指数法对土样的Cu污染现状进行评价;采用改进BCR法分析了其中种植油菜的22土样Cu的赋存形态,并对油菜各部位Cu含量进行了测定,结合富集系数和转运系数,分析了Cu在土壤-油菜系统中的迁移累积规律。结果表明,以湖北省土壤背景值评价,土壤受到不同程度的Cu污染,重污染所占比例最高;以国家土壤环境质量二级标准(GB15618-1995)评价,污染等级以轻污染为主,且有25%的土壤未污染;污染最严重的3个区域是铜绿山、大箕铺和龙角山。油菜土壤中Cu的形态分布规律为残渣态可还原态可氧化态酸溶态,酸溶态占全量的比例与p H有显著的负相关关系,相关系数r=-0.471(n=22)。油菜各部位Cu含量分布呈现根壳籽茎的规律,Cu主要累积在油菜根部,土壤-籽富集系数均值仅为0.11;9个油菜样籽粒的Cu含量超过了食品安全限值,籽粒的Cu含量与土壤酸溶态Cu含量之间的相关性最强。     

硒对植物的毒害作用

采用室内培养的方法，研究了硒对小麦、黄瓜等植物的毒害作用。结果表明，低浓度的Na2SeO3能够促进植物体内叶绿素前体物质ALA（δ－aminolevalinic acid）的合成，有利于植物的生长发育；但浓度较高时（0.1mmol）会导致植物抗逆境反应物质ABA的增加，抑制ALA的合成，影响植物的正常生长发育；浓度达到1.0mmol时，ABA含量开始下降，植物出现毒害症状。同时也发现，外源6BA对硒的毒害有明显的拮抗作用。     

土壤弹尾目昆虫对铜污染的急性毒理初步研究

随着土壤环境重金属污染的加剧,有关重金属污染土壤的风险评估受到关注。对土壤质量评价的方法长期以来集中在检测重金属污染物质在土壤中的浓度及化学形态等方面,而对于重金属、土壤和生物之间的相互作用很少考虑,因而难以全面评估重金属对土壤环境的生态毒性效应。重金属污染土壤的     

重金属铜、镉对蝌蚪毒性的研究

试验研究铜、镉对蝌蚪的急性毒性和联合毒性结果表明,Cu~(2 )对蝌蚪24h、48h、96h的半致死浓度LC_(50)分别为0.201mgg/kg、0.138mg/kg和0.118mg/kg,Cd~(2 )对蝌蚪24h、48h和96h的LC_(50)分别为32.1mg/kg、23.3mg/kg和18.9mg/kg。Cu~(2 )和Cd~(2 )共存对蝌蚪24h、48h和96h联合毒性的相加指数AI分别为1.03、1.2和1.20,均为协同作用。     

植物铝毒害机理的研究

本文综述了植物铝毒害机理的研究概况，包括铝毒害症状、铝的吸收、转运和信号传递、铝毒害机理等方面，提出了植物铝毒害机理研究中存在的问题。     

Simultaneous determination of copper and iron in plant material by an automated method

Abstract

Existing colorimetric manual methods for copper and iron have been adapted for simultaneous analysis by an automated method. Fifty samples per hour can be assayed. Calculation of results as parts per million in dry matter has been eliminated by a standardized weighing technique of the plant material.     

红壤中重金属的复合污染及污染指数

A field experiment was conducted to study the effects of Pb,Cd,Cu,Zn and As coexisting in red soil on growth of rice (Oryza sativa L.) mung bean(Vigna rabiata(Linn.) Wilczek),alfalfa(Medicago sativa L.),Slash pine(Pinus elliottii Engelm.)and aspen(Populus L.).Results showed that rice,mung bean and alfalfa were significantly influenced by combined poollution of the heavy metals,the contents of Pb,Cd and As in rice grains greatly exceeded the National Standards for Food Hygiene of China.Heavy metals at a high concentration seriously retarded growth of mung bean and alfalfa,but not so obviously with slash pine and aspen.The composite index is suggested for evaluating the relativity of combined pollution with heavy metals in soil.     

Determining higher fatty acid levels in plant materials 1

The higher fatty acids (HFA) are important plant constituents that are implicated in the grass tetany hazard in livestock. A method is given whereby a technician can analyze 12 forage samples daily for HFA content.

The method consists of saponifying the plant material in ethanol and KOH and extracting the subsequently acidified HFA with petroleum ether. The petroleum ether phase is evaporated and the HFA residue is dissolved in ethanol and then titrated with standardized isobutanolic KOH in the absence of O₂ by using a N₂ atmosphere. A standard plant sample, analyzed over a 37‐day period, had a mean of 136 mmol H⁺ /kg ±4.5, where a 0.1 mmol H⁺ / l palmitic standard was determined with an accuracy of 99 ± 1.9%.     

紫色土施用磷酸盐肥料对玉米铜毒害的缓解

A pot experiment was conducted to evaluate the effects of phosphorus fertilizer in inhibiting the copper toxicity to maize(Zea mays L.) in neutral purple soil. Results indicated that the growth of the shoot and roots of maize plant was obviously reduced by copper and the height and biomass were significantly negatively correlated to the application levels of copper (r = -0.899^**~-0.994^**) at no P and low P (100 mg kg^-1). However, the maize biomass was relatively increased and the high Cu (100 and 200 mg kg^-1) induced toxicity of maize was greatly alleviated in all treatments with medium P (300 mg kg^-1 ) and high P (500 mg kg^-1). To maintain the normal growth of maize plant (≥3.68 g pot^-1), the critical application rates of phosphorus fertilizer should be 160, 210, 300 and 500 mg P kg^-1 at 10, 50, 100 and 200 mg Cu kg^-1 levels of the soil, respectively. The increases in polyphenol oxidase and catalase activities in maize leaf and dehydrogenase activity in roots by phosphorus fertilizer were in the order of medium P>high P>low P>no P. Activities of polyphenol oxidase and catalase were significantly positively correlated to the application levels of copper (r =0.892^**~0.924^**), whereas that of dehydrogenase was just reverse (r = -0.966^**) at no P. Medium and high P repressed the influence of copper on activities of three enzymes. Phosphorus fertilizer reduced the copper concentrations of maize roots and leaf and the change ranges of the P/Cu ratio of maize roots and the P/Cu, N/Cu and K/Cu ratios of maize leaf. The three ratios of maize leaf were 256^**71.5, 2643^**839 and 1133^**440 at normal growth of maize plant, respectively. Soil available Cu could be markedly cut down by application of phosphorus fertilizer, especiallly at high phosphorus level.     

施用高级脂肪酸对烤烟生理特性及烟叶化学成分的影响

研究了在烤烟的旺长期施用三种不同种类的高级脂肪酸对烤烟生理生化特性和烟叶化学成分的影响,结果表明,油酸在烤烟生长后期在降低叶片叶绿素含量、硝酸还原酶的活性、提高转化酶和淀粉酶活性方面都优于十六酸、硬脂酸和对照处理;油酸在提高烟叶中的磷含量和降低烟叶中的氯和烟碱含量方面以及化学成分的协调性方面优于其它处理,有利于烟叶品质的改善。从外观上看,油酸处理的烟叶落黄好,油分足。     

Physiological responses of pepper plant (Capsicum annuum L.) to drought stress

Water shortage is the most important factor constraining agricultural production all over the world. New irrigation strategies must be established to use the limited water resources more efficiently. This study was carried out in a completely randomized design with three replications under the greenhouse condition at Shahrekord University, Shahrekord, Iran. In this study, the physiological responses of pepper plant affected by irrigation water were investigated. Irrigation treatments included control [full irrigation (FI) level] and three deficit irrigation (DI) levels—80, 60, and 40% of the plant's water requirement called DI₈₀, DI₆₀, and DI₄₀, respectively. A no plant cover treatment with three replications was also used to measure evaporation from the soil surface. Daily measurements of volumetric soil moisture (VSM) were made at each 10-cm intervals of the soil column, considered as a layer. The differences between the measured VSM and the VSM in the next day and evaporation rate at the soil surface at the same layer of the bare soil with no plant cover treatment were calculated. Eventually, by considering the applied and collected water in each treatment, evapotranspiration (ET_C) and root water uptake in each layer per day were estimated. Furthermore, fruit number per plant, fresh fruit weight/day, root fresh/dry weights, shoot fresh/dry weights, root zone volume, root length and density, crop yield, and water use efficiency (WUE) were measured under different water treatments. The results showed that the maximum and minimum of all the studied parameters were found in the FI and DI₄₀ treatments, respectively. ET_C in the DI₈₀, DI₆₀, and DI₄₀ treatments were reduced by 14.2, 37.4, and 52.2%, respectively. Furthermore, applying 80, 60, and 40% of the plant's water requirement led to the reduction in crop yield by 29.4, 52.7, and 69.5%, respectively. The averages of root water uptakes in the DI₈₀, DI₆₀, and DI₄₀ treatments reduced by 17.08, 48.72, and 68.25%, respectively. WUE and crop yield also showed no significant difference in the FI and DI₈₀ treatments. Moreover, in the DI₈₀ treatment, the reduced rate of water uptake was less than the reduced rate of plant's applied water. According to these results, it can be concluded that 20% DI had no significant reduction on the yield of pepper, but above this threshold, there was an adverse effect on the growth and yield. Therefore, for water management in the regions with limited water resources, rate of plant's applied water can be decreased by around 20%.     

二元含Hg(Ⅱ)重金属混合物对发光细菌的联合毒性

本文采用二次二因子回归通用旋转组合实验设计,以明亮发光杆菌(photobacterium phosphoreum)T3变种作为毒性测试物种,研究Hg2 Pb2 、Hg2 Cd2 和Hg2 Cr6 等二元含Hg(Ⅱ)重金属混合物的联合毒性作用和主因子作用,建立了3个相应的数学模犁.结果表明,Hg2 、Pb2 、Cd2 与Cr6 对明亮发光杆菌的毒性有显著的正效应.3个含Hg2 二元重金属混合物对发光细菌的联合毒性作用不同,总体上Hg2 与Pb2 以协同作用为主,Hg2 与Cd2 为相加作用,而Hg2 与Cr6 以拮抗作用为主.从单因子作用效应的角度看,3个混合物中对发光细菌的毒性Hg2 大于另一重金属,即Hg2 为主因子.发光细菌法作为一种快速、操作方便、成本低廉的生物监测方法,将在农产品污染物毒性评价和农产品安全快速检测中有着广泛的应用前景.