Publications by authors named "Shahbaz Talib Sahi"

6 Publications

  • Page 1 of 1

Complete Genome Sequence of the Type Strain Pectobacterium punjabense SS95, Isolated from a Potato Plant with Blackleg Symptoms.

Microbiol Resour Announc 2020 Aug 6;9(32). Epub 2020 Aug 6.

Institute for Integrative Biology of the Cell (I2BC), CEA CNRS University Paris-Saclay, Gif-sur-Yvette, France

is a newly described species causing blackleg disease in potato plants. Therefore, by the combination of long (Oxford Nanopore Technologies, MinION) and short (Illumina MiSeq) reads, we sequenced the complete genome of SS95, which contains a circular chromosome of 4.793 Mb with a GC content of 50.7%.
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http://dx.doi.org/10.1128/MRA.00420-20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7409842PMC
August 2020

Species Diversity of and Causing Potato Blackleg Disease in Pakistan.

Plant Dis 2020 May 8;104(5):1492-1499. Epub 2020 Mar 8.

Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France.

Potato blackleg is caused by a diverse species of pectinolytic bacteria. In Pakistan, approximately 90% of the pathogens involved belong to Survey (2014 to 2017), sampling, and isolation from different potato growing areas of Punjab, Pakistan depicted an overall disease incidence of approximately 15%. Thirty-six pectinolytic strains confirmed through biochemical and pathogenicity testing were characterized via gene to identify them at the species level. To further validate the identification, one strain from each species SS26 (), SS28 (), SS70 (), SS90 (), SS95 (), and SS96 () were selected for draft genome sequencing and multilocus sequence analysis of 13 housekeeping genes (, , , , , , , , , , , , and ). Phylogenetic analysis revealed considerable genetic diversity in the genus . DNA-DNA hybridization and average nucleotide identity values of the strains selected for genome sequencing were determined with other reference and strains. Moreover, all six representative strains were also phenotypically characterized on the basis of metabolism of different carbon sources. Overall, on the basis of genotypic and phenotypic characteristics, these 36 isolates were grouped into six species: , , , , , and .
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http://dx.doi.org/10.1094/PDIS-08-19-1743-REDOI Listing
May 2020

Pectobacterium punjabense sp. nov., isolated from blackleg symptoms of potato plants in Pakistan.

Int J Syst Evol Microbiol 2018 Nov 21;68(11):3551-3556. Epub 2018 Sep 21.

2​Institute for Integrative Biology of the Cell (I2BC), CEA CNRS Univ. Paris-Sud, University Paris-Saclay, 91198 Gif-sur-Yvette, France.

Pectobacterium isolates SS95, SS54 and SS56 were collected from a potato field in the Chiniot district in the plains of the Punjab province, Pakistan. Sequencing of the gapA barcode revealed that these strains belong to a novel phylogenetic group separated from P.ectobacterium wasabiae and Pectobacterium parmentieri species. Furthermore, multilocus sequence analyses of 13 housekeeping genes (fusA, rpoD, acnA, purA, gyrB, recA, mdh, mtlD, groEL, secY, glyA, gapA and rplB) clearly distinguished the type strain, SS95, from its closest relatives, i.e. P. parmentieri RNS 08-42-1A and P. wasabiae CFBP3304, as well as from all the other known Pectobacteriumspecies. In silico DNA-DNA hybridization (<44.1 %) and average nucleotide identity (<90.75 %) values of strain SS95 compared with other Pectobacterium type strains supported the delineation of a new species. Genomic and phenotypic comparisons permitted the identification of additional traits that distinguished the Pakistani isolates from all other known Pectobacterium type strains. The name Pectobacterium punjabense sp. nov. is proposed for this taxon with the type strain SS95 (=CFBP 8604=LMG 30622).
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http://dx.doi.org/10.1099/ijsem.0.003029DOI Listing
November 2018

Performance of sorghum cultivars for biomass quality and biomethane yield grown in semi-arid area of Pakistan.

Environ Sci Pollut Res Int 2018 May 23;25(13):12800-12807. Epub 2018 Feb 23.

Department of Plant Pathology, University of the Agriculture, Faisalabad, Pakistan.

Biomass is a promising renewable energy source and its significance is escalating in the context of climate change and depletion of fossil foils. This study was conducted for two consecutive years 2016 and 2017, using five sorghum cultivars, i.e., JS-263, Jawar-2011, Hagari, JS-2002, and YS-2016, in order to determine the best cultivars in terms of dry matter yield, chemical composition, and biomethane yield grown under semi-arid conditions in Pakistan. The results revealed that sorghum cultivars responded differently in terms of growth, biomass yield, chemical composition, and methane yield. Cultivars Jawar-2011 produced maximum leaf area index, leaf area duration, crop growth rate, plant height, and leaves per plant, however, they were comparable with Sorghum-2016, whereas cultivar JS-2002 performed poorly among the tested cultivars. Similarly, cultivar Jawar-2011 produced maximum dry matter yield (16.37 t ha) similar to that of YS-2016, further cultivar JS-2002 performed poorly and gave lower dry matter yield (12.87 t ha). The maximum protein concentration (10.95), neutral detergent fibers (61.20), and lignin contents (5.55) found in Jawar-2011 were comparable with those in YS-2016, while the lowest neutral detergent fiber and lignin contents were found in JS-2002. Although JS-2002 produced the highest specific methane yield per kilogram of volatile solids, it was overcompensated by Jawar-2011 owing to higher dry matter yield per hectare. These results suggested that cultivar Jawar-2011 can be grown successfully in semi-arid conditions of Pakistan in order to get good biomass yield along with higher methane yield.
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http://dx.doi.org/10.1007/s11356-018-1575-4DOI Listing
May 2018

Multiple Resistances Against Formulated Organophosphates, Pyrethroids, and Newer-Chemistry Insecticides in Populations of Helicoverpa armigera (Lepidoptera: Noctuidae) from Pakistan.

J Econ Entomol 2015 Feb 24;108(1):286-93. Epub 2015 Jan 24.

Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria 3010, Australia.

Field populations of Helicoverpa armigera Hübner from 15 localities across the Punjab, Pakistan, were assessed by the leaf dip method for resistance against formulated organophosphates, pyrethroids, and newer insecticide groups. Resistance levels in H. armigera have been incrementally increasing for organophosphate and pyrethroid insecticides after decades of use in Pakistan. Resistance ratios (RRs) documented for organophosphates were 24- to 116-fold for profenofos and 22- to 87-fold for chlorpyrifos. For pyrethroids, RRs were 3- to 69-fold for cypermethrin and 3- to 27-fold for deltamethrin. Resistance levels against newer chemistries were 2- to 24-fold for chlorfenapyr, 1- to 22-fold for spinosad, 1- to 20-fold for indoxacarb, 1- to 18-fold for abamectin, and 1- to 16-fold for emamectin benzoate. Resistant populations of H. armigera were mainly in the southern part of the Punjab, Pakistan. The most resistant populations were collected from Pakpattan, Multan, and Muzzafargarh. Of the nine insecticides tested, LC50 and LC90 values were lower for newer insecticide groups; resistance levels were moderate to very high against organophosphates, very low to high against pyrethroids, and very low to low against the newer-chemistry insecticides. These findings suggest that the newer-chemistry insecticides with different modes of action could be included in insecticide rotations or replace the older insecticides. Supplementing the use of synthetic insecticides with safer alternatives could help to successfully lower the farmer's reliance on insecticides and the incidence of resistance due to repeated use of insecticides against major insect pests.
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http://dx.doi.org/10.1093/jee/tou037DOI Listing
February 2015

Biotoxicity assessment of pyrene in soil using a battery of biological assays.

Arch Environ Contam Toxicol 2012 Nov 1;63(4):503-12. Epub 2012 Sep 1.

Institute of Environmental Science and Technology, Zhejiang University, Hangzhou, People's Republic of China.

A test battery, composed of a range of biological assays, was applied to evaluate the ecological health of soil aged for 69 days and spiked with a range of pyrene levels (1.04, 8.99, 41.5, 72.6, 136, and 399 μg g(-1) dry soil; Soxhlet-extracted concentrations after 69 days of aging). Chinese cabbage (Brassica rapa), earthworm (Eisenia fetida), and bacteria (Vibrio fischeri) were used as test organisms to represent different trophic levels. Among the acute ecotoxicity bioassays used, the V. fischeri luminescence inhibition assay was the most sensitive indicator of pyrene toxicity. We observed >8 % light inhibition at the lowest concentration (1.04 μg g(-1)) pyrene, and this inhibition increased to 60 % at 72.6 μg g(-1). The sensitivity ranking for toxicity of the pyrene-contaminated soil in the present study was in the following decreasing order: root elongation of Chinese cabbage < earthworm mortality (14 days) < earthworm mortality (28 days) < luminescence inhibition (15 min) < luminescence inhibition (5 min). In addition, genotoxic effects of pyrene were also evaluated by using comet assay in E. fetida. The strong relationship between DNA damage and soil pyrene levels showed that comet assay is suitable for testing the genotoxicity of pyrene-polluted soil. In addition, tail moment was well correlated with soil pyrene levels (r (2) = 0.99). Thus, tail moment may be the most informative DNA-damage parameter representing the results of comet assay. Based on these results, the earthworm DNA damage assay and Microtox test are rapid and sensitive bioassays and can be used to assess the risk of soil with low to high levels of hydrocarbon pollution. Furthermore, an analysis of the toxic effects at several trophic levels is essential for a more comprehensive understanding of the damage caused by highly contaminated soil.
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http://dx.doi.org/10.1007/s00244-012-9793-0DOI Listing
November 2012