109 results on '"Naureen Akhtar"'
Search Results
102. First Report of Aspergillus parvisclerotigenus Rot in Garlic Bulbs From Pakistan
- Author
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Amna Shoaib, U. Amin, Naureen Akhtar, and Zoia Arshad Awan
- Subjects
Aflatoxin ,biology ,Aspergillus flavus ,Plant Science ,biology.organism_classification ,Pathogenicity ,Spore ,Microbiology ,chemistry.chemical_compound ,chemistry ,Botany ,Fungal morphology ,Mycotoxin ,Medicinal plants ,Agronomy and Crop Science ,Ribosomal DNA - Published
- 2015
103. First Report of Alternaria longipes Causing Leaf Spot of Potato Cultivar Sante in Pakistan
- Author
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Amna Shoaib, R. Hafeez, S. Akhtar, and Naureen Akhtar
- Subjects
biology ,Spots ,fungi ,Hyphal tip ,food and beverages ,Plant Science ,Alternaria ,biology.organism_classification ,Spore ,Conidium ,Horticulture ,Germination ,Botany ,Leaf spot ,Cultivar ,Agronomy and Crop Science - Abstract
Potato (Solanum tuberosum) is one of the most important vegetable crops worldwide, including Pakistan. During surveys from November to February of 2011 to 2013 in Sahiwal (Punjab), a severe leaf spot disease, new to farmers, was recorded. Symptoms consisted of 1- to 3-mm diameter black circular necrotic spots and appeared on the leaves of 2- to 3-week-old plants. Disease incidence was ~70 to 80%. This disease was localized to few fields in Sahiwal on potato variety Sante and to our knowledge, this has not been found on other areas or potato varieties in Pakistan. Fungi were isolated from randomly selected diseased plants. Ten infected plants were brought to the laboratory in sterilized polyethylene bags. One infected leaf per plant was selected for pathogen isolation. Infected parts of leaves were cut into ~2 mm2 pieces. Leaf pieces were surface sterilized for 1 min with 0.5% sodium hypochlorite and then inoculated aseptically onto 2% malt extract agar (MEA) (Sigma, Dorset, UK) and incubated at 25 ± 2°C for 3 to 4 days in the dark. Hyphal tip transfer from emerging colonies was performed to obtain pure cultures. Initial microscopic examination of pure fungal colonies revealed Alternaria as the likely causal organism. For morphology-based identification, five isolates from separate infected leaves were grown on MEA as well as potato carrot agar (PCA) for 7 days. All isolates showed similar morphological characters including dusty greenish black, floccose colonies with regular and smooth margins reaching 3 to 4.5 cm in diameter on MEA and sporulation with well-defined zones of growth. Aerial hyphae produced long branches that bore lateral chains of 1 to 7 conidia. Conidia were pointed at the tip, ovoid or ellipsoid, ranged from 18 to 40 × 5 to 12 μm with 4 to 8 transverse and 0 to 1 longitudinal septa. No conidial beak was present. Conidial color darkened from dull olive to brown as the culture matured. Based on morphology, the pathogen was identified as Alternaria longipes (1). A pure culture of a fungal pathogen was submitted to First Fungal Culture Bank of Pakistan (FCBP1355) for future reference. To confirm the morphology-based identification, the rDNA internal transcribed spacer (ITS) nucleotide sequence was amplified using ITS1 forward and ITS4 reverse primers (2). The amplicon of 537 bp was sequenced and submitted to GenBank under accession KJ806191. A BLASTn search using the KJ806191 sequence revealed it to be 99% identical to around 20 different strains of A. longipes deposited in GenBank including leaf spot pathogens of another Solanaceaeous member, Nicotiana tabacum (AY154684) and Asteraceous plant, Atractylodes macrocepha (JQ004404). Pathogenicity testing was performed in the greenhouse at 30 ± 2°C. Pots (16 × 9 cm) were filled with sterilized soil. Since spores of Alternaria sp. are known to survive in soil or plant debris, soil was sterilized and inoculated with 106 spore suspension of the isolated pathogen before sowing the potato seeds. Control pots were not inoculated. Approximately 10 days after plant germination, the previously observed disease symptoms appeared on leaves and A. longipes was re-isolated from the necrotic areas of leaves, thus fulfilling Koch's postulates. Plants in control treatments were asymptomatic. Pathogenicity tests were repeated three times. To our knowledge, this is the first report of A. longipes leaf spot of potato cultivar Sante from Pakistan. However, the distribution of this disease is confined to the area where it was observed, but it could be a threat for potato crop if not managed timely. References: (1) E. G. Simmons. Alternaria: An identification manual. CBS, Fungal Biodiversity Center Utrecht, The Netherlands, 2007. (2) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990.
- Published
- 2014
104. A familial hypomagnesemia--hypercalciuria (Manz syndrome)
- Author
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Naureen, Akhtar, Farkhanda, Hafeez, and Tahir Masood, Ahmad
- Subjects
Male ,Nephrosclerosis ,Adolescent ,Humans ,Calcium ,Magnesium Deficiency - Abstract
We report a case of a rare inherited tubular disorder of linked transport of magnesium and calcium at the level of ascending limb of loop of Henle, characterized by hypomagnesemia, hypercalciuria and nephrocalcinosis, known as "Manz syndrome," who presented with polyuria, nystagmus and recurrent episodes of tetany with radiological evidence of rickets and nephrocalcinosis.
- Published
- 2005
105. First Report of New Postharvest Rot in Ginger Rhizome by Aspergillus parvisclerotigenus in Pakistan
- Author
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Amna Shoaib, Naureen Akhtar, and Zoia Arshad Awan
- Subjects
food.ingredient ,biology ,Inoculation ,business.industry ,Aspergillus flavus ,Plant Science ,biology.organism_classification ,Spore ,Biotechnology ,Rhizome ,Horticulture ,food ,Postharvest ,Agar ,Zingiber officinale ,business ,Agronomy and Crop Science ,Ginger Rhizome - Abstract
Ginger (Zingiber officinale) rhizome is widely used in Pakistan as a spice. During the summer of 2013, several ginger sellers in a local vegetable market of Lahore, Pakistan, reported a green powdery mass of an unidentified pathogen that rotted a considerable quantity of ginger in its packaging. As far as we know, this disease was limited to stored rhizomes and not reported in fields. A survey was conducted in August to September of 2013 in three different vegetable markets in Lahore to collect infected samples. From each of three survey points from individual markets, 20 bags (10 kg each) were selected randomly. Average incidence of decay (by weight) was found to be 45%. Initial symptoms appeared as discoloration, soft and slippery skin with abundant green sporulation. Ten samples (rhizomes) from each market were brought to the laboratory for further studies. Isolation of the causal agent was carried out on two growth media: malt extract agar (MEA) and Czapek Dox agar (CZA). Inoculation was carried out by direct transfer of visible green spores as well as transferring a small fragment of surface sterilized infected rhizome to the media. Inoculated media plates were incubated at 25°C for 3 to 4 days. Emerging fungal colonies were sub-cultured to get pure cultures. The fungal colony was powdery, green, 3.5 to 4 cm in diameter, and without zonation after 7 days of incubation. Sclerotia were brown to black and globose. Conidial heads were columnar and biseriate, occasionally unseriate. Conidiophores were 1 to 2.5 mm long. Vesicles were sub-globose to globose and 25 to 30 μm wide. Metulae were 12 to 18 μm high and phialides were 6 to 12 μm. Conidia were globose to sub-globose, green, and 4 to 5 μm in diameter. Based on morphology, the fungus was identified as Aspergillus parvisclerotigenus (1). The identity of the pathogen was confirmed by ITS sequence analysis of two different isolates. For this, ITS1-5.8S-ITS2 nucleotide sequence of ~560 bp was amplified using total fungal genomic DNA as a template and ITS1 forward (5′-TCCGTAGGTGAACCTGCGG-3′) and ITS4 reverse primer (5′-TCCTCCGCTTATTGATATGC-3′) (2). Sequences from both isolates were 100% similar with each other. A BLAST search showed that this sequence had 99% homology with that A. parvisclerotigenus CBS 121.62 (EF409240.1). A culture of the fungus was deposited in First Fungal Culture Bank of Pakistan (FCBP1352) and the nucleotide sequence of ITS region to GenBank (KJ445022). For completion of Koch's postulates, a spore suspension (105 spores/ml) from a 1-week-old culture was prepared. Ten surface-disinfested, air-dried ginger rhizomes were placed on sterilized wet blotting papers in a glass beaker and inoculated by spore suspension using a hand sprayer. Similarly, 10 control rhizomes were sprayed with sterile distilled water. Rhizomes were incubated at 25°C for 7 days. The experiment was replicated three times. The same symptoms noticed in the vegetable markets were observed in 80% of the inoculated rhizomes while control rhizomes remained healthy. Re-isolation of the pathogen from symptomatic rhizomes fulfilled Koch's postulates. Poor hygiene is thought to be the main cause of rotting; therefore, this disease is not a threat to ginger if stored properly. To our knowledge, this is the first report of postharvest ginger rhizome rot from Pakistan caused by A. parvisclerotigenus. References: (1) J. Varga et al. Stud. Mycol. 69:57, 2011. (2) T. J. White et al. In: PCR Protocols: A Guide to Methods and Applications, page 315. Academic Press, San Diego, CA, 1990.
- Published
- 2014
106. First Report of Leaf Spot of Rice Caused by Alternaria arborescens in Pakistan
- Author
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Naureen Akhtar, S. Mushtaq, and Uzma Bashir
- Subjects
Oryza sativa ,Spots ,biology ,fungi ,food and beverages ,Plant Science ,biology.organism_classification ,Horticulture ,chemistry.chemical_compound ,Intergenic region ,Agronomy ,chemistry ,Sodium hypochlorite ,Alternaria arborescens ,Leaf spot ,Paddy field ,Cultivar ,Agronomy and Crop Science - Abstract
Rice (Oryza sativa) is one of the most profitable and popular cereal crops in Pakistan. In July 2012, symptoms consisting of circular, black, necrotic spots, 2 to 4 mm in diameter, were observed on leaves of a commonly grown rice cultivar, Basmati-198, in private rice fields at Lahore (Punjab). This disease was observed later on rice cultivar KSK-133 grown at Faisalabad (Punjab) during the same cropping season. Disease incidence was ~35% and 25% for Basmati-198 and KSK-133, respectively. To our knowledge, the pathogen was confined only in these areas and cultivars and was not present on other rice varieties or crops. Ten infected plants were selected randomly from each field of two rice cultivars and one infected leaf for each of the 10 infected plants was selected for the isolation of fungal pathogen. Necrotic lesions were cut into pieces of ~2 mm2, surface-disinfected with 0.5% sodium hypochlorite, placed on 2% malt extract agar (MEA) (Sigma, Dorset, UK), and incubated at 25 ± 2°C for 4 to 5 days. Emerging fungal colonies were transferred aseptically to fresh MEA petri plates for purification. Alternaria spp. were consistently recovered from infected leaves. Three isolates per variety were selected for detailed morphological studies. Each isolate was grown at 25°C on MEA and potato carrot agar (PCA) for 7 days. All isolates displayed similar morphological features including black radiate, floccose colonies with irregular margins, 6 to 7 cm in diameter on MEA and 2 to 3 cm with 1 to 2 pairs of concentric growth rings on PCA. Conidial chains were not crowded with 1 to 10 conidia per branch and bearing several lateral branches. Conidiophores were tapering and narrow, 40 to 200 × 2 μm. Conidia were ovoid within a size range of 10 to 30 × 5 to 14 μm, with 1 to 5 transverse and 1 longitudinal septum. Conidial color darkens from a dull tan to a medium brown as the culture matures. Based on morphology, the pathogen was identified as Alternaria arborescens (1). A pure culture of the pathogen was deposited in First Fungal Culture Bank of Pakistan (FCBP) with accession FCBP1351. Identification based on morphology was verified by sequencing the internal transcribed spacer (ITS) region. For this, a DNA fragment of ~650 bp was amplified using total genomic DNA as template and ITS1 and ITS4 primers (2). The nucleotide sequence of the ITS region was submitted to GenBank under accession KF679683. Comparison of the sequence with those in GenBank revealed that the sequence was 99% identical with A. arborescens, isolate ALT-242 (KC415808), causing Eucalyptus leaf spot in India and strain STE-U4345 (AF404667), a causal pathogen of apple core rot in South Africa. Pathogenicity testing was performed on both cultivars. One-month-old plants grown in greenhouse were sprayed with 10 ml of spore suspension (2 × 105 spores/ml) as well as 10 ml of this spore suspension in soil at the time of sowing. Control plants were sprayed with sterilized water. The plants were covered with plastic bags for 48 h and kept under observation for 2 weeks in a glasshouse at 30 ± 2°C. Lesions appeared on leaves after 10 days of inoculation whereas control plants remained healthy. Pathogenicity tests were repeated in triplicate. Similar disease symptoms and re-isolation of A. arborescens fulfilled Koch's postulates. To our knowledge, this is the first report of A. arborescens leaf spot of rice in Pakistan. At present, the distribution of this disease is limited to the fields where it was observed. References: (1) E. G. Simmons. Alternaria: An Identification Manual. CBS, Fungal Biodiversity Center Utrecht, The Netherlands, 2007. (2) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990.
- Published
- 2014
107. Herbicidal Activity of Aqueous Extracts of Cirsium arvense and Ageratum conyzoides Against Weeds of Wheat
- Author
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., Naureen Akhtar, primary, ., Arshad Javaid, additional, and ., Rukhsana Bajwa, additional
- Published
- 2001
- Full Text
- View/download PDF
108. Antifungal Activity of Allelopathic Plant Extracts I. Effect of Aqueous Extract of Three Allelopathic Asteraceous Species on Growth of Aspergillii
- Author
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., Rukhsana Bajwa, primary, ., Naureen Akhtar, additional, and ., Arshad Javaid, additional
- Published
- 2001
- Full Text
- View/download PDF
109. Influence of Fe doping on the structural, optical and thermal properties of α-MnO2 nanowires.
- Author
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Amjad Khan, Arbab Mohammad Toufiq, Fawad Tariq, Yaqoob Khan, Rafaqat Hussain, Naureen Akhtar, and Shams ur Rahman
- Published
- 2019
- Full Text
- View/download PDF
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