Publications by authors named "Waqas Ashraf"

7 Publications

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and management of (Kofoid and White) Chitwood and (Taub.) Butler in cotton using organic's.

Saudi J Biol Sci 2021 Jan 19;28(1):1-9. Epub 2020 Aug 19.

Research Center for Advanced Materials Science (RCAMS), King Khalid University, P.O. Box 9004, Abha 61413, Saudi Arabia.

Root-knot nematodes (Kofoid and White) Chitwood and (Taub.) Butler, fungus, are very dangerous root damaging pathogens. Present study was planned to establish a chemical control of these root deteriorating pathogens under lab conditions as well as in field. Maximum death rate of nematode juveniles and minimum numbers of nematode eggs hatched were recorded in plates treated with Cadusafos (Rugby® 100G) @12 g/100 ml and Cartap® (4% G) @9g/100 ml. Chemical treatment of with Trifloxystrobin + Tebuconazole (Nativo®) @0.2 g/100 ml and Mancozeb + Matalaxyl (Axiom) @0.25 g/100 ml significantly controlled the mycelial growth in plates. The best treatments tested in laboratory were applied in field as protective and curative treatments. Results proved that chemical control of root-knot nematode and root rot fungi by tested chemicals at recommended time and dose is a significant management technique under field conditions.
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http://dx.doi.org/10.1016/j.sjbs.2020.08.023DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7785457PMC
January 2021

First report of brown leaf spot of rice caused by Bipolaris zeicola in Pakistan.

Plant Dis 2020 Aug 17. Epub 2020 Aug 17.

University of Agriculture Faisalabad, 66724, Entomology, Faisalabad, Punjab, Pakistan;

Rice (Oryza sativa L.) is one of the highly consumed cereal grain crops in Pakistan. In September 2017, leaf samples of cultivar Basmati-385 showing brown to dark brown spots (5 to 9 mm in diameter) that were oval or cylindrical in shape with a chlorotic yellow halo and grayish tan centers were collected from fields near the University of Agriculture, Faisalabad (31.43633 N 73.05981 E). Average disease incidence was 69% in six rice fields that were sampled for diseased plants with visible symptoms. To isolate the pathogen, from 20 diseased leaves, 5 mm2 segments from the margins of lesions were cut, rinsed with sterile distilled water (SDW), surface disinfected by 70% ethanol and again rinsed with SDW. The samples were dried on sterilized filter paper discs, plated on potato dextrose agar (PDA) and incubated at 27°C for 5 to 7 days. Twelve isolates were sub-cultured and single-sporing was performed to obtain pure cultures. Fungal isolates with light to dark gray in color, thick or fluffy aerial mycelium, circular and smooth margins were obtained after 7 days of incubation. Conidia were 47-83 μm × 10-17 μm (n=100), with 4 to 10 distosepta, dark or olivaceous brown, straight or moderately curved, and the cells at the ends occasionally looked paler than those in the middle. Conidiophore of the fungus were simple, smooth, cylindrical, septate, and straight to flexuous. These characteristics resembled those of Bipolaris zeicola (Stout) Shoemaker (Manamgoda et al. 2014). For molecular identification, genomic DNA (isolate SU-11) was extracted and the internal transcribed spacer (ITS) region, large subunit (LSU) of ribosomal DNA, translation elongation factor (tef), glyceraldehyde 3-phosphate dehydrogenase (gpd), and RNA polymerase II second largest subunit (rpb2) genes were amplified and sequenced by using the primers ITS1-F/ITS4-R (White et al. 1990), LROR-F/LR5-R (Schoch et al. 2012), EF1-983F/EF1-2218R (Rehner and Buckley 2005), GPD1F/GPD2R (Berbee et al. 1999), and 5F2/7CR (O'Donnell et al. 2007), respectively. BLASTn searches showed 100% homology with the LSU and rpb2 sequences of B. zeicola (GenBank Accession Nos. MH876201 and HF934842) and 98-99% similarity with ITS, tef, and gpd sequences of B. zeicola (GenBank Accession Nos. KM230398, KM093752 and KM034815). The sequences of ITS, LSU, tef, gpd, and rpb2 were deposited in GenBank with accession numbers MN871712, MN877767, MN867685, MN904511 and MT349837, respectively. To fulfill Koch's postulates, 25 greenhouse-grown rice plants (cv. Basmati-385) at 2- to 3-leaf stage were spray inoculated with a spore suspension (105 spores/ml; isolate SU-11) prepared in SDW. Plants were covered with plastic wraps to maintain humid conditions for 24 hours and incubated at 27°C for one week. Similarly, ten non-inoculated plants sprayed with SDW served as controls. After one week, observed symptoms were similar to those from natural infections and no disease symptoms were observed on the non-inoculated plants. The experiment was repeated twice and the pathogen was re-isolated from the infected leaves and characterized morphologically. Globally, B. zeicola has also been reported to cause the leaf spot of rice and maize plants (Sivanesan 1987; Kang et al. 2018). To our information, this is the first report of B. zeicola causing brown leaf spot of rice in Pakistan. The increasing risk of this fungal pathogen in the rice-growing areas of Pakistan need a rigorous exploration and outreach effort to develop effective management practices.
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http://dx.doi.org/10.1094/PDIS-04-20-0838-PDNDOI Listing
August 2020

Integration of entomopathogenic fungi and eco-friendly insecticides for management of red palm weevil, (Olivier).

Saudi J Biol Sci 2020 Jul 19;27(7):1811-1817. Epub 2019 Dec 19.

Biology Department, Faculty of Science, King Khalid University, P.O. Box 9004, Abha 61413, Saudi Arabia.

Red palm weevil () is a voracious pest of date palm worldwide. Pakistan ranks sixth in date palm production globally. Losses to date palm plantations in Pakistan sometimes surpass 10%-20%. Most of the traditional management strategies used by farmers have been found insignificant to combat this voracious pest. The entomopathogenic fungi, [QA-3(L) and QA-3(H)] and insecticides, Nitenpyram (Active 10% SL) [NIT (L) and NIT (H)] were applied to larval (2nd, 4th, and 6th), pupal and adult stages of . Integration or alone application of fungi with insecticides at different concentration under laboratory conditions. Combined application was depicted additive and synergistic interactions. Contrarily, highest cumulative mortality (100%) was recorded in 2nd instar larvae as compared to later instar larvae at combined application. The maximum pupal and adult mortality remained 89% and 66% respectively after treatment with [QA-3 (H) + NIT (L)]. The combination of at higher concentration whereas Nitenpyram at lower dose was found more lethal to larvae, pupae and adults of . This signifies the need of combining and bio-rational insecticides that can reduce the cost of management with least harm to environment and natural enemies.
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http://dx.doi.org/10.1016/j.sjbs.2019.12.018DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7296496PMC
July 2020

Carotenoid-loaded nanocarriers: A comprehensive review.

Adv Colloid Interface Sci 2020 Jan 7;275:102048. Epub 2019 Nov 7.

State Key Laboratory of Food Science and Technology, Jiangnan University, Jiangsu, Wuxi 214122, China.

Carotenoids retain plenty of health benefits and attracting much attention recently, but they have less resistance to processing stresses, easily oxidized and chemically unstable. Additionally, their application in food and pharmaceuticals are restricted due to some limitations such as poor bioavailability, less solubility and quick release. Nanoencapsulation techniques can be used to protect the carotenoids and to uphold their original characteristics during processing, storage and digestion, improve their physiochemical properties and enhance their health promoting effects. The importance of nanocarriers in foods and pharmaceuticals cannot be denied. This review comprehensively covers recent advances in nanoencapsulation of carotenoids with biopolymeric nanocarriers (polysaccharides and proteins), and lipid-based nanocarriers, their functionalities, aptness and innovative developments in preparation strategies. Furthermore, the present state of the art encapsulation of different carotenoids via biopolymeric and lipid-based nanocarriers have been enclosed and tabulated well. Nanoencapsulation has a vast range of applications for protection of carotenoids. Polysaccharides in combination with different proteins can offer a great avenue to achieve the desired formulation for encapsulation of carotenoids by using different nanoencapsulation strategies. In terms of lipid based nanocarriers, solid lipid nanoparticles and nanostructure lipid carriers are proving as the encouraging candidates for entrapment of carotenoids. Additionally, nanoliposomes and nanoemulsion are also promising and novel-vehicles for the protection of carotenoids against challenging aspects as well as offering an effectual controlled release on the targeted sites. In the future, further studies could be conducted for exploring the application of nanoencapsulated systems in food and gastrointestinal tract (GIT) for industrial applications.
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http://dx.doi.org/10.1016/j.cis.2019.102048DOI Listing
January 2020

Kinetic flux vector splitting scheme for solving non-reactive multi-component flows.

Comput Biol Chem 2019 Dec 19;83:107107. Epub 2019 Sep 19.

Department of Mathematics, COMSATS University, Islamabad, Pakistan. Electronic address:

This paper is about multi-component flow. There is no doubt that multi-component flow has a wide range of applications, specially in aerospace it plays a vital role during reentry of space ship into earth's atmosphere thats why it cannot be neglected for a proper vehicle design. In this paper one- and two-dimensional homogenous multi-component flow models are numerically investigated by using a high resolution splitting scheme and this scheme is known as Kinetic Flux Vector Splitting scheme. This scheme preserves positivity conditions and resolves shocks, rarefaction and contact discontinuity. The scheme is based on splitting of flux functions. Moreover Runge-Kutta time stepping technique with MUSCL-type initial reconstruction is used to guarantee higher order accurate solution. This work is first done by Qamar and Warnecke (2004) for the homogeneous multi-component flow equations using central scheme, here we investigate the same work using kinetic flux vector splitting scheme (KFVS) and compared the results with central scheme to verify the efficiency of studied scheme.
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http://dx.doi.org/10.1016/j.compbiolchem.2019.107107DOI Listing
December 2019

A kinetic flux vector splitting scheme for shallow water equations incorporating variable bottom topography and horizontal temperature gradients.

PLoS One 2018 31;13(5):e0197500. Epub 2018 May 31.

COMSATS Institute of Information Technology, Park Road, Chak Shahzad Islamabad, Pakistan.

This paper is concerned with the derivation of a well-balanced kinetic scheme to approximate a shallow flow model incorporating non-flat bottom topography and horizontal temperature gradients. The considered model equations, also called as Ripa system, are the non-homogeneous shallow water equations considering temperature gradients and non-uniform bottom topography. Due to the presence of temperature gradient terms, the steady state at rest is of primary interest from the physical point of view. However, capturing of this steady state is a challenging task for the applied numerical methods. The proposed well-balanced kinetic flux vector splitting (KFVS) scheme is non-oscillatory and second order accurate. The second order accuracy of the scheme is obtained by considering a MUSCL-type initial reconstruction and Runge-Kutta time stepping method. The scheme is applied to solve the model equations in one and two space dimensions. Several numerical case studies are carried out to validate the proposed numerical algorithm. The numerical results obtained are compared with those of staggered central NT scheme. The results obtained are also in good agreement with the recently published results in the literature, verifying the potential, efficiency, accuracy and robustness of the suggested numerical scheme.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0197500PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5979031PMC
December 2018

Genetic detection of peste des petits ruminants virus under field conditions: a step forward towards disease eradication.

BMC Vet Res 2017 Jan 25;13(1):34. Epub 2017 Jan 25.

National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan.

Background: The devastating viral disease of small ruminants namely Peste des petits ruminants (PPR) declared as target for "Global Eradication" in 2015 by the Food and Agriculture Organization (FAO) and the World Organization for Animal Health (OIE). For a successful eradication campaign, molecular diagnostic tools are preferred for their specificity, efficacy and robustness to compliment prophylactic measures and surveillance methods. However, molecular tools have a few limitations including, costly equipment, multi-step template preparation protocols, target amplification and analysis that restrict their use to the sophisticated laboratory settings. As reverse transcription-loop mediated isothermal amplification assay (RT-LAMP) has such an intrinsic potential for point of care diagnosis, this study focused on the genetic detection of causative PPR virus (PPRV) in field conditions. It involves the use of a sample buffer that can precipitate out virus envelope and capsid proteins through ammonium sulphate precipitation and exposes viral RNA, present in the clinical sample, to the LAMP reaction mixture.

Results: The test was evaluated using 11 PPRV cultures, and a total of 46 nasal swabs (n = 32 collected in the field outbreaks, n = 14 collected from experimentally inoculated animals). The RT-LAMP was compared with the reverse transcription-PCR (RT-PCR) and real-time quantitative RT-PCR (RT-qPCR) for its relative specificity, sensitivity and robustness. RT-LAMP detected PPRV in all PPRV cultures in or less than 30 min. Its detection limit was of 0.0001TCID (tissue culture infective dose-50) per ml with 10-fold higher sensitivity than that of RT-PCR. In 59.4% of the field samples, RT-LAMP detected PPRV within 35-55 min. The analytical sensitivity and specificity of the RT-LAMP were equivalent to that of the RT-qPCR. The time of detection of PPRV decreased by at least forty minutes or 3-4 h in case of in the RT-LAMP as compared with the RT-qPCR and the RT-PCR, respectively.

Conclusions: The sensitive and specific RT-LAMP test developed in this study targeting a small fragment of the N gene of PPRV is a rapid, reliable and applicable molecular diagnostic test of choice under the field conditions. RT-LAMP requiring minimal training offers a very useful tool for PPR diagnosis especially during the "Global PPR Eradication Campaign".
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http://dx.doi.org/10.1186/s12917-016-0940-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5264299PMC
January 2017