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Suthar V.,Pakistan National Agricultural Research Center
Environmental monitoring and assessment | Year: 2014

Natural and chemically enhanced phytoextraction potentials of maize (Zea mays L.) and sesbania (Sesbania aculeata Willd.) were explored by growing them on two soils contaminated with heavy metals. The soils, Gujranwala (fine, loamy, mixed, hyperthermic Udic Haplustalf) and Pacca (fine, mixed, hyperthermic Ustollic Camborthid), were amended with varying amounts of ethylenediaminetetraacetic acid (EDTA) chelating agent, at 0, 1.25, 2.5, and 5.0 mM kg(-1) soil to enhance metal solubility. The EDTA was applied in two split applications at 46 and 60 days after sowing (DAS). The plants were harvested at 75 DAS. Addition of EDTA significantly increased the lead (Pb) and cadmium (Cd) concentrations in roots and shoots, uptake, bioconcentration factor, and phytoextraction rate over the control. Furthermore, addition of EDTA also significantly increased the soluble fractions of Pb and Cd in soil over the controls; the maximum increase of Pb and Cd was 13.1-fold and 3.1-fold, respectively, with addition of 5.0 mM EDTA kg(-1)soil. Similarly, the maximum Pb and Cd root and shoot concentrations, translocation, bioconcentration, and phytoextraction efficiency were observed at 5.0 mM EDTA kg(-1) soil. The results suggest that both crops can successfully be used for phytoremediation of metal-contaminated calcareous soils. Source


Ghafoor A.,Pakistan National Agricultural Research Center | McPhee K.,North Dakota State University
Euphytica | Year: 2012

In this contribution we review the state of the art for genetic resistance to powdery mildew, caused by Erysiphe pisi, in pea (Pisum sativum L.) and potential use of marker-assisted selection (MAS) for developing disease resistant cultivars. Powdery mildew is important in many production regions worldwide and reduces yield and crop quality when present in epidemic proportions. Although genetic resistance to powdery mildew is available (er1 and er2) and has been durable since its characterization in 1969, recently a new dominant gene (Er3) has been reported in Pisum fulvum, a wild relative of pea that is different from previously reported er1 and er2. The efficacy of these genes may be at risk from the point of view of new pathotypes and pathogens. Erysiphe trifolii has been reported that was not previously known as a pathogen of pea powdery mildew. A continued search for new and diverse resistant sources remains a priority in pea breeding and special emphasis should be paid to selection of resistance that will prolong durability of existing resistance genes. Marker assisted selection is a new emerging approach for target breeding that has been intensively employed especially in cereals and has recently got popularity among legume breeders. With the advancement of genomic research, especially related to quantitative traits loci, the MAS is potentially anticipated future technique for routine plant breeding that is scarce in legumes at present. In pea, various DNA markers have been reported linked to er1, er2 and Er3 at varying distances in different mapping populations that are currently being used in breeding programs. Currently MAS of single gene is the most powerful approach and successes have been witnessed. If single marker is not close enough to the gene of interest then two flanking markers are considerably utilized to improve the correct identification that is being successfully employed in MAS for powdery mildew resistance in pea. © 2011 Springer Science+Business Media B.V. Source


Rashid A.,Quaid-i-Azam University | Nawaz S.,UK Environment Agency | Barker H.,UK Environment Agency | Ahmad I.,Pakistan National Agricultural Research Center | Ashraf M.,National University of Sciences and Technology
Journal of Chromatography A | Year: 2010

A procedure based on QuEChERS extraction and a simultaneous liquid-liquid partition clean-up was developed. The procedure involved extraction of hydrated soil samples using acetonitrile and clean-up by liquid-liquid partition into n-hexane. The hexane extracts produced were clean and suitable for determination using gas chromatography-tandem mass spectrometry (GC-MS/MS). The method was validated by analysis of soil samples, spiked at five levels between 1 and 200 μgkg-1. The recovery values were generally between 70 and 100% and the relative standard deviation values (%RSDs) were at or below 20%. The procedure was validated for determination of 19 organochlorine (OC) pesticides. These were hexachlorobenzene (HCB), α-HCH, β-HCH, γ-HCH, heptachlor, heptachlor epoxide (trans), aldrin, dieldrin, chlordane (trans), chlordane (cis), oxychlordane, α-endosulfan, β-endosulfan, endosulfan sul-fate, endrin, p,p′-DDT, o,p′-DDT, p,p′-DDD and p,p′-DDE. The method achieved low limits of detection (LOD; typically 0.3 μgkg-1) and low limits of quantification (LOQ; typically 1.0 μgkg-1). The method performance was also assessed using five fortified soil samples with different physico-chemical proper-ties and the method performance was consistent for the different types of soil samples. The proposed method was compared with an established procedure based on Soxtec extraction. This comparison was carried out using six soil samples collected from regions of Pakistan with a history of intensive pesticide use. The results of this comparison showed that the two procedures produced results with good agree-ment. The proposed method produced cleaner extracts and therefore led to lower limits of quantification. The proposed method was less time consuming and safer to use. The six samples tested during this com-parison showed that soils from cotton growing regions contained a number of persistent OC residues at relatively low levels (<10 μgkg-1). These residues were α-HCH, γ-HCH, heptachlor, chlordane (trans), p,p′-DDT, o,p′-DDT, p,p′-DDD, p,p′-DDE, β-endosulfan and endosulfan sulfate. © 2010 Elsevier B.V. Source


Yunus A.W.,Pakistan National Agricultural Research Center | Bohm J.,University of Veterinary Medicine Vienna
Poultry Science | Year: 2013

The purpose of this study was to observe the effects of low doses of aflatoxin B1 (AFB1) on responses to common vaccines and levels of serum cations in broilers. Male broilers at 7 d of age were fed control (no AFB1), a 75 μg of AFB1/kg (75 ppb of AFB1) diet, or a 750 μg of AFB1/kg (750 ppb of AFB1) diet. The 750 ppb of AFB1 diet resulted in a temporary increase in ELISA titers against Newcastle disease virus (P = 0.014) and infectious bursal disease virus (P = 0.005) during wk 2 and 4 of exposure, respectively, compared with the control diet. Conversely, lower (P ≤ 0.01) serum protein concentrations were found in broilers under the 750 ppb AFB1 diet during wk 2 and 4. During wk 2 of exposure, lower serum levels of potassium were noted in birds under both the 75 (P = 0.037) and 750 ppb (P = 0.000) AFB1 diets compared with those under the control diet. During wk 5, higher serum magnesium (P = 0.004), and sodium (P = 0.000) under the 750 ppb AFB1 diet were found compared with the control diet. These data indicate that low dietary levels of AFB1 can temporarily increase or decrease the studied serological variables in broilers depending upon the stage of exposure. © 2013 Poultry Science Association Inc. Source


Eqani S.A.-M.-A.-S.,Quaid-i-Azam University | Malik R.N.,Quaid-i-Azam University | Mohammad A.,Pakistan National Agricultural Research Center
Environmental Geochemistry and Health | Year: 2011

Organochlorine pesticides (OCPs), viz. β-hexachlorocyclohexane (β-HCH), γ-HCH, aldrin, dieldrin, endrin, heptachlor, endosulfan-I, endosulfan-II, heptachlor endoepoxide, heptachlor exoepoxide, mirex, dicofol, o,p′-dichlorodiphenyltrichloroethane (o,p′-DDT), p,p′-dichlorodiphenyltrichloroethane (p,p′-DDT), dichlorodiphenyldichloroethane (DDD), and dichlorodiphenyltrichloroethylene (DDE) and 12 other physicochemical parameters were measured in surface sediments from River Chenab during two sampling seasons (summer and winter, 2007) to evaluate spatial and temporal trends of sediment pollution. Hierarchical agglomerative cluster analysis identified three groups of sites based on spatial similarities in physicochemical parameters and OCP residual concentrations. Spatial discriminant function analysis (DFA) segregated 14 parameters, viz. dicofol, endosulfan-I, heptachlor endoepoxide, dieldrin, DDD, DDE, endosulfan-II, o,p′-DDT, p,p′-DDT, pH, electrical conductivity (EC), Cl-1, total P (%), and silt, which explained 96% of total variance between spatial groups. γ-HCH was the most frequently detected (63%) pesticide, followed by DDD (56%). The ratio of DDTs to their metabolites indicated current input and anaerobic biodegradation. Temporal DFA highlighted aldrin, heptachlor endoepoxide, Cl-1, total P, and EC as important variables which caused variations between summer and winter. DDTs were relatively more prevalent as compared to other OCPs in the sediments samples during both seasons. DDT metabolites were detected at greater frequencies and concentrations in winter, whereas DDT isomers were more prevalent in summer sediment samples. Factor analysis identified agricultural and industrial activities as major sources of sediment OCP contamination. Concentrations of γ-HCH, heptachlor endoepoxide, dieldrin, and DDTs (isomers and metabolites) in all sediment samples were well above interim sediment quality guidelines (ISQGs) and probable effect limits (PEL) given by Canadian Sediment Quality Guidelines (CSQGs). © 2010 Springer Science+Business Media B.V. Source

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