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Papers by Muhammad Fahim Abbas

World Journal of Biology and Biotechnology, 2020

The experiment was conducted to classify the maximum glutenin protein possessed Pakistani bread w... more The experiment was conducted to classify the maximum glutenin protein possessed Pakistani bread wheat genotype for superlative chapati making quality by ten yield-related parameters. The studied germplasm was acquired from NARC, Pakistan, and planted in randomized-complete-block-design with four replicates at the screen house of the Genetics Department. Data were assessed via Duncan’s test, correlation analysis, SDS-PAGE, and cluster analysis. Duncan’s test conceded that Pirsabak-85 had the highest plant height, flag leaf area, biomass, grain yield plantˉ1, harvest index, and protein content. While, the correlation studies showed that plant height, tillers plantˉ1 (r = 0.649), fertile tillers plantˉ1 (r = 0.713),biomass (r = 0.861), spike length (LS), thousand-grain weight and harvest index had a positive higher significant association with grain yield plantˉ1. The SDS-PAGE analysis resolved 30 diverse high and low molecular weight bands, ranging from 200 kDa to 28 kDa glutenin subu...

In Pakistan, roses are commercially valuable as ornamentals and for perfumes, essential oils, ros... more In Pakistan, roses are commercially valuable as ornamentals and for perfumes, essential oils, rose syrup, and herbal tea. During 2015-16, circular to oval black spots (2 to 3 mm in diameter) were observed on roses in the cities of Islamabad and Rawalpindi. A total of 35 symptomatic leaves were surface sterilized with 1% sodium hypochlorite for 2 min and then rinsed three times with sterile distilled water. Excised segments (3 mm 2) of surface sterilized tissue were transferred to potato dextrose agar (PDA) and incubated at 25 ± 2°C. After 5 days, white colonies developed from 25 samples and later turned black or golden brown. The conidia were borne singly or in short chains and were obpyriform to obclavate, 10 to 40 × 6.2 to 17.60 µm with 0 to 3 longitudinal and 2 to 6 transverse septa. The morphological characters matched those of Alternaria alternata (Fr.) Keissl (Simmons 2007). For confirmation of pathogenicity, three asymptomatic mature rose leaves were surface sterilized with 1% sodium hypochlorite and then sprayed with single spore suspensions (10 6 conidia ml-1) of each isolate; leaves that were sprayed with sterile distilled water served as negative controls. The leaves were incubated at 25 ± 2°C in sterile glass chambers at 70% relative humidity and the experiment was conducted twice. Symptoms were noted 5 days after inoculation and were consistent with those from samples collected originally from the infected plants, whereas no symptoms occurred on the negative control leaves. The fungus reisolated from the symptomatic tissues was morphologically indistinguishable from the fungus used for inoculation. For genetic identity, the internal transcribed spacer (ITS1, 5.8S, and ITS2) region of ribosomal DNA (rDNA) and beta tubulin (BT) gene of ALT-1 were amplified with ITS1/ITS4 and BT1/BT2 primers, respectively (Berbegal et al. 2014) and sequences were submitted to NCBI (GenBank accession nos. KY609180 and KY609181, respectively). Both sequences exhibited 100%

Anthracnose is a destructive postharvest (Palou et al. 2016) and foliar disease of loquat (Eriobo... more Anthracnose is a destructive postharvest (Palou et al. 2016) and foliar disease of loquat (Eriobotria japonica). Anthracnose was observed in loquat orchards of Taxila (33°44′13″N. 72°47′57″E) and Wah Cantt (33°46′17″N, 72°45′3″E) areas of Pakistan during April 2013 to July 2015. Leaf symptoms initiated as small circular necrotic spots that enlarged into reddish brown, round to irregular necrotic brown areas visible on adaxial and abaxial surfaces. Fruit exhibited dark brown sunken lesions, which later turned into black, hard, and shriveled mummies. Anthracnose affected 39 and 23% of the plants in Taxila and Wah Cantt, respectively. Leaf (120) and fruit (80) samples were collected from 10 loquat orchards. Small pieces (5 to 10 mm2) were cut from the margins of lesions on fruits and leaves, surface disinfested with 1% sodium hypochlorite for 2 min, washed three times in sterilized distilled water, dried, and placed aseptically on Czapek Dox agar (CDA) plates (Thom and Raper 1945), followed by incubation at 25°C for 4 to 5 days. White cottony mycelia with a concentric zone of shiny orange conidial masses were consistently observed on CDA after 4 days. Conidia were hyaline, cylindrical with rounded ends, and aseptate, measuring 12.7 to 18.8 × 3.3 to 6.7 µm (mean 15.5 × 4.8 μm, n = 50 conidia). Appressoria were light brown, ovate to obovate, and 6 to 10 × 4.5 to 7.5 µm (mean 8.6 × 5.8 μm). All these characteristics matched with those described for Colletotrichum gloeosporioides (Sawant et al. 2012). For verification of pathogen identity, DNA of two representative isolates (TAX-1 and WAH-1) was extracted and three loci including the internal transcribed spacer (ITS) region, actin (ACT), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were amplified using primers ITS1/ITS4, ACT512F/ACT783R, and GDF/GDR, respectively (Weir et al. 2012). The purified PCR products were sequenced by Macrogen Inc., Korea. GenBank accession numbers for isolate TAX-1 (KR075160, KX185669, KX378683) and WAH-1 (KR075159, KX216403, KX379458) were assigned for ITS, ACT, and GAPDH, respectively. BLAST analyses showed 98 to 100% identity with C. gloeosporioides accessions HQ874906, KF712382, and HQ022565 for ITS, ACT, and GAPDH, respectively. In order to determine the pathogenicity of the isolates, conidial suspensions (1.5 × 105 conidia/ml) were prepared for each of 35 isolates, which were sprayed until run-off on three detached healthy, unwounded leaves and fruit for each isolate. Three control leaves and fruit were inoculated with sterile distilled water and placed at 25 ± 2°C. The symptoms on all inoculated leaves initiated as pinpoint, round, reddish brown, circular necrotic spots after 3 days that later coalesced into irregular spots. On fruit, dark brown necrotic sunken lesions developed after 4 days, which later covered the whole fruit. Symptoms were similar to those observed in the orchards, and control leaves and fruit remained symptomless. This is the first report of C. gloeosporioides infecting loquat in Pakistan. Further studies are needed to ascertain the best control measures for the management of the disease in commercial orchards.

Strawberry (Fragaria × ananassa Duch.) is grown on 1,500 ha as a commercial crop in many regions ... more Strawberry (Fragaria × ananassa Duch.) is grown on 1,500 ha as a commercial crop in many regions of Pakistan. To gain a clearer picture of the occurrence of diseases on commercial strawberries, 60 fields (10 fruits/field) were randomly surveyed in prominent strawberry growing areas of Islamabad (Islamabad Capital Territory), Punjab and KPK Provinces in the years 2014-15 and 2015-16. Fruit rot accompanied by thick, white fluffy masses of mycelium was observed frequently; disease incidence ranged from 15 to 56%. Portions of symptomatic fruit were excised at the lesion margin, surface disinfested with 2% sodium hypochlorite for about 2 to 3 min, and then rinsed three times in sterilized distilled water, plated on Czapek Dox (CZ) agar, and incubated for 3 to 7 days at 25 ± 2°C. Pure cultures obtained after serial hyphal tip transfers were examined for morphological characters. Colonies were fast growing, fluffy to appressed, cottony white to pale cream, and produced pale/yellowish coloration on the bottom of plates. Colonies produced both microconidia and macroconidia; microconidia were plentiful, oval to kidney shaped, 7 to 16 × 1.5 to 5 µm, and monophialides were usually borne in false heads, whereas macroconidia were fusiform, slightly curved, 25 to 41 × 3 to 7 µm, with 3 to 6 septations and somewhat elongated apical margins. Chlamydospores were abundant, thick walled, spherical, and 5 to 11 µm in diameter (Leslie and Summerell 2006). Pathogenicity tests were performed by inoculating one representative isolate (NAS-11) on two asymptomatic strawberry fruit in three replications with one 10-μl drop per fruit of a conidial suspension (10 6 to 10 7 conidia/ml); sterile distilled water droplets on separate fruit were used as controls. Inoculated and control fruit were incubated in humid chambers at 25 ± 2°C. After 2 to 4 days, fluffy mycelial growth and rot symptoms appeared that were identical to the appearance of symptomatic fruit in the field, whereas control fruit were asymptomatic. Isolate (NAS-11) DNA was extracted and the ITS and EF regions were amplified and sequenced (White et al. 1990). Results of sequences were deposited in GenBank

In Pakistan, loquat (Eriobotrya japonica) is a major fruit crop for local and export markets. In ... more In Pakistan, loquat (Eriobotrya japonica) is a major fruit crop for local and export markets. In a 2014 survey, several fruit rots were observed in 34 loquat orchards located in Taxila, Wahcantt, Khanpur, Tret, Chatar, Muree, Kalar Kahar, and Choa Saidan Shah districts of Punjab Province; disease incidence ranged from 40 to 60%. Soft, dark brown to black lesions were observed on immature and mature fruit. A total of 89 symptomatic fruit were surface sterilized with 1% sodium hypochlorite for 2 min and rinsed three times with sterile distilled water. Excised segments (4 mm 3) of sterilized tissue were transferred to potato dextrose agar (PDA) and incubated at 25 ± 2°C. After 1 week, white, fluffy, fast-growing colonies with septate and hyaline hyphae were observed; conidiophores were unbranched. A total of 71 isolates were used for morphological characterization. Microconidia were hyaline, ovoid, and 5.9 × 9.8 to 2.1 × 3.9 μm. Macroconidia were hyaline, curved and ranging from 19.8 × 29.9 to 3.9 × 5.8 μm. PCR was used to amplify the internal transcribed spacer (ITS) and translation elongation factor (EF) regions of isolates PAK51 and PAK52 with universal ITS1/4 and EF1/2 primers, respectively (Geiser et al. 2004; White et al. 1990). Sequence comparison of ITS (accession nos. KY000479 and KY000480) and EF (KY00081 and KY000482) revealed 99.0 to 99.5% homology with isolates of Fusarium solani (Mart.) Sacc. (teleomorph = Nectria hematococca (Berk. & Br.) available in GenBank and FUSARIUM-ID databases. To confirm pathogenicity, 10-μl aliquots of spore suspension (10 6 spores/ml) of the same two isolates were pipetted onto nonwounded and wounded asymptomatic healthy loquat fruits (three fruit per isolate) and sterile distilled water was used for a negative control. The pathogenicity tests were conducted twice and fruit were incubated at 25 ± 2°C in sterile glass chambers. Soft lesions consistent in appearance with the original symptoms were observed on inoculated loquat fruits, whereas no symptoms were recorded on the negative control fruit. The morphological characteristics of the fungus that was reisolated from each of the inoculated fruit was identical to that of the original cultures. Fusarium sp. has been reported to caused fruit rot

and S. Ali and M. Idrees, Plant Pathology Research Institute, AARI Faisalabad, Pakistan. Citation... more and S. Ali and M. Idrees, Plant Pathology Research Institute, AARI Faisalabad, Pakistan. Citation | Open Access. Berseem (Trifolium alexandrinum) is an annual clover growing in numerous agricultural regions of Pakistan, providing about 51% of total fodder demand in the country. During February 2014, fluffy white mycelium was observed on aerial parts of berseem plants in multiple fields in the Faisalabad (31°25′15.7620″ N, 73°5′21.4584″ E) district of Punjab Province, Pakistan. Diseased plants also exhibited water-soaked lesions, resulting in wilting and bleaching and eventually leading to crown rot. When temperatures rose from 21 to 25°C, hard, black sclerotia (2 to 4 × 16 mm) were observed outside and inside of infected stems. About 17% of plants in affected fields died before harvest. The pathogen was isolated from sclerotia that were air dried at room temperature (25°C), then surface sterilized for 1 to 2 min in 1% NaOCl and rinsed twice in sterile distilled water before transferring to half-strength acidified potato dextrose agar (PDA) amended with ampicillin (100 µg/ml). After 4 to 5 days, the resulting hyphae were subcultured and maintained on PDA at 15 to 20°C. The fungus produced fluffy white mycelial growth. Hyphae were hyaline and septate, later developing dark, black, irregular sclerotia (5 to 10 mm diameter).

In Pakistan, loquat (Eriobotrya japonica) in an emerging fruit and provides well economic return ... more In Pakistan, loquat (Eriobotrya japonica) in an emerging fruit and provides well economic return to growers. Percentage disease incidence of necrotic leaf spot (Alternaria mali) ranged from 25 to 46.16% in Taxila, Wahcant, Khanpur, Kalar Kahar, Choa Saiden Shan, Tret, Chatar and Murree. 38 isolates were characterized for cultural, morphological and pathogenic variations. Light to dark olivacious colonies were appraised, cottony to velvety with regular to irregular margins and variations in size and shape of conidia were observed between isolates. Length of conidiophores was ranging from 24.6 to 68.5 µm and nine was the highest septation in isolate ALT7WT1. Nucleotide sequences of inter transcribed spacer region (ITS1, 5.8S, ITS2) from 4 highly virulent isolates were submitted in the database of NCBI under accession numbersKR232489, KR232490, KT154010 and KT154011 respectively. Evolutionary history was computed with available sequences of A. mali, A. lternata, A. zinnae and A. tenuissima which were reported from Pakistan, USA, Sweden, Newzeland and India. Evolutionary tree showed4 different sub-trees and submitted sequences were observed in A. mali sub-tree. Amino acid sequences were exhibiting 100 to 99% genetic homology with A. mali isolate (FCBP1343) reported form Pakistan. Amino acid sequences were compared with FCBP1343 and differences at position number 18 (valine was replaced with glutamate), 57 (glutamine with leucine), 84 (alanine with glycine), 163 (glutamine instead of histidine) and 171 (serine was replaced with phenylalanine) were observed. Cultural, morphological, pathogenic and molecular characterization of A. mali associated with necrotic leaf spot of loquat was recorded first time in Pakistan.

The loquat (Eriobotrya japonica Lindl.) is achieving significant value in Pakistan. During the ye... more The loquat (Eriobotrya japonica Lindl.) is achieving significant value in Pakistan. During the year 2014-2015, reddish brown circular spots were observed on leaves; these spots increased in size and coalesced to form oblong lesions. Samples were cut into small pieces (3 mm2), surface sterilized with sodium hypochlorite and transferred on Malt Extract Agar (MEA). These samples were incubated at 24±2°C and dark brown colonies with large stroma were observed. Septate condiophores were unbranched or simple and geniculate with dark brown scar. Brown conidia were straight to pyriform with 3-4 cells (large and curved center cell), ranging in size from 6.9 to 20.99 μm and produced apically in a sympodial manner. Morphological characterization was similar to Curvularia lunata (Ellis, 1971). PCR was used for amplification of rDNA region (White et al., 1990) and sequences of PAK34 and PAK35 was submitted to GenBank under accession Nos. KT280007 and KT280008. Both isolates were exhibiting 99% genetic homology with previously reported C. lunata isolates (KM246260, KM246262). Spore suspension (1 × 106 spore/ml) was sprayed on healthy loquat seedlings, kept in glasshouse at 30°C and plants developed lesions similar to those observed on naturally infected plants. Isolation was performed from inoculated loquat plants and morphological characterizations were similar to naturally isolated pathogens. Curvularia leaf spot diseases caused by C. lunata have been previously found on small evergreen tree. To our knowledge, this is the first report worldwide of C. lunata causing leaf spots on loquat.

Protein (CP) gene were used for molecular diagnosis of PVY in Polymerase Chain Reaction (PCR) and... more Protein (CP) gene were used for molecular diagnosis of PVY in Polymerase Chain Reaction (PCR) and sequence of Pakistani isolate (JQ518267) exhibited 795 nucleotides with maximum composition of adenine followed by guanine, thymine or uracil and cytosine respectively. Physical and chemical properties of CP gene were computed and different bioinformatics tools clearly indicate that amplified gene is hydrophilic, non-allergen and highly conserved region. The final sequence was further compared with ordinary, common, necrotic and recombinant strains of PVY. The phylogenetic tree clearly indicates four different clusters and Pakistani isolate falls in first cluster exhibiting the high degree of nucleotide homology (99.98%) with previously reported isolates of Pakistan.

In the present study, bacterial and fungal agents involved in sudden death syndrome (SDS) in chil... more In the present study, bacterial and fungal agents involved in sudden death syndrome (SDS) in chillies and their relative contribution in the development of disease complex were investigated. Out of eight microbial agents isolated from wilted chilli plants, three pathogenic species viz. Ralstonia solanacearum, Fusarium oxysporum and Rhizoctonia solani were identified and characterized depending upon their morphological, cultural and biochemical behavior. These isolates induced wilting, when inoculated on susceptible chilli cultivar California Wonder under greenhouse conditions. All the pathogens induced wilt symptoms; however, the wilting was more rapid in case of R. solanacearum followed by F. oxysporum and R. solani. Disease symptoms were more prominent when three pathogens inoculated in combinations. However, R. solanacearum and R. solani intriguingly, showed no symptoms even after thirty days of inoculation upon repeated trials. On the other hand, the interactive studies of three pathogens indicated that the symptoms development and seedlings mortality were higher than the rest of combinations or by the individual pathogen.

Edible potato (Solanum tuberosum L.) is ranked fourth among the staple food crop and fifth for hu... more Edible potato (Solanum tuberosum L.) is ranked fourth among the staple food crop and fifth for human consumption. It is a vegetative propagated crop and a large number of pests and diseases can be carried from one generation to the next. Pathogens including fungi, bacteria, viruses and nematodes caused significant yield losses in field and storage conditions. Blights (Phytophthora infestans, Alternaria solani and Phoma spp.), powdery scab (Spongospora subterranea), wart (Synchytrium endobioticum), watery wound rot (Pythium ultimum), gangrene (Phoma exigua var. foveta), silver scurf (Helminthosporium solani), pink rot (Phytophthora erythroseptica), dry rot (Fusarium spp.), black scurf (Rhizoctonia solani), skin spot (Polyscytalum pustulans), wilt of potato (Verticillium sp.) and charcoal rot (Macrophomina phaseolina) are the most destructive fungal diseases and reduced the quality, quantity and market value of potato tubers. This brief review paper demonstrates the symptoms and management strategies against important fungal diseases of potato.

Potato virus X (PVX) is among top ten most economically damaging plant viruses in the world and i... more Potato virus X (PVX) is among top ten most economically damaging plant viruses in the world and its increasing incidence is getting an alarming situation in potato crop of Pakistan. During two consecutive years (2010-11 and 2011-12), the incidence of PVX was recorded in potato fields at Rawalpindi, Islamabad, Faisalabad and Sahiwal. The samples were collected and subjected to Double Antibody Sandwiched (DAS) Enzyme Linked Immunosorbant Assay (ELISA) and average incidence of PVX was determined about 16.86% (OD405nm 1.38) during 2010-11 and 27.10% (OD405nm 0.479) in 2011-12. The infectivity of the virus was assayed through mechanical inoculation on Nicotiana tabacum cv. Samsun, N. rustica, Datura stramonium, Chenopodium sp. Gomphrena and Capsicum annuum producing local lesion, mosaic and mottling symptoms. Coat protein (CP) gene specific sense and antisense primer successfully amplified a 750bp fragments through Polymerase Chain Reaction (PCR) assay.

Potato is one of the main cash crops for the farmer and also contributes a considerable amount in... more Potato is one of the main cash crops for the farmer and also contributes a considerable amount in Gross Domestic Product of Pakistan because it is cultivated as a garden vegetable and also on commercial scale. In high altitude valley, potatoes are grown as summer crop while in the plains and low valleys three consecutive crops can be grown per year. Potato crop provides 12-15 times more yield and calories production is also higher than wheat maize and rice while the average yield of potato crop in Pakistan is low as compared to other potato growing countries. Potato growers introduced high yielding foreign potato varieties which have significantly enhanced the yield of potato crop along with new viral problems and among these, Potato Virus A (PVA), Potato Virus M (PVM), Potato Virus S (PVS), Potato Virus X (PVX), Potato Virus Y (PVY), Potato Leaf Roll Virus (PLRV) and Potato Mop-top Virus (PMTV) have been reported in spring, summer and autumn potato crop along with 83% yield losses. In Pakistan, a large number of potato germ-plasms were certified through Enzyme Linked Immunosorbant Assay (ELISA) which is unable to detect the virus at initial stage of infection and new molecular tools like Polymerase Chain Reaction (PCR) assay were introduced for successful, sensitive and more reliable confirmation of viruses. Different percentage incidence of PVA and PVM was reported from main potato growing areas of Pakistan and no molecular optimization along with nucleotide evidence of these two viruses was reported from Pakistan. PCR assay were developed for molecular detection of PVX, PVY, PMTV, PVS and PLRV while no nucleotide evidence of PVS is still reported from Pakistani while coat protein (CP) gene sequence of PVX, PVY and PLRV from Pakistani isolates is available at the data bank of National Center for Biotechnology Information. The increasing incidence of PVY is getting an alarming position in potato crop of Pakistan and nucleotide sequence of CP gene reveals the presence of new strain in Pakistani potato while the nucleotide evidence of CP gene of PVX from a Pakistani isolate exhibiting the maxim homology with USSR isolate.

In Pakistan, tomato (Solanum lycopersicum) has achieved second position among the most important ... more In Pakistan, tomato (Solanum lycopersicum) has achieved second position among the most important vegetable crops and Root Knot Nematode (Meloidogyne javanica) caused economic losses in tomato production. Different quantity of marigold (Tagetes erecta L.) leaves along with different concentration of antagonistic fungus (Paecilomyces lilacinus (Thom) Samson) were used to control Root Knot Nematode on tomato plants in a glasshouse experiment. Significant increase in fresh and dry weight of root and shoot along with plant height was recorded with maximum quantity of marigold (10g/kg) and antagonistic fungus (1010 3) while there was no significant increase in any parameter at low quantity (2, 4 and 6g/kg) and concentration (410 3 and 410 3). Maximum increase and decrease in number of galls, eggs masses, soil and root population, eggs per eggs mass and total population of nematode was recorded in the absence and presence of marigold and antagonistic fungus respectively. All parameters of host along with pathogen were statistically similar at intermediate doze of fungus and marigold.

Lentil (Lens culinaris Medik) is ranked as sixth most important pulse crop of the world. Conventi... more Lentil (Lens culinaris Medik) is ranked as sixth most important pulse crop of the world. Conventional breeding in lentil is hampered due to inadequate genetic variability, high degree of self pollination and small flowers. Cotyledonary nodes (CN), epicotyls and hypocotyls of two varieties of lentil namely Masoor-85 and 2009 were used as explants source to establish a protocol for genetic transformation system using Agrobacterium tumefaciens strain (EHA105 and LBA4404) containing pGreen plasmid vector with GUS gene. Cotyledonary nodes (93%) and epicotyls (56%) of Masoor-2009 showed maximum growth on shooting media as compared with Masoor-85. Epicotyls of Masoor-2009 and Masoor-85 showed 56% and 45% regeneration with 2-3 shoots developed on each epicotyl. The performance of EHA105 and LBA4404 in GUS expression was 70% and 60% respectively. Stable integration of GUS gene was also confirmed through polymerase chain reaction (PCR) assay.

Potato viruses caused 83% yield losses in potato crops of Pakistan. Potato Virus X (PVX) is in th... more Potato viruses caused 83% yield losses in potato crops of Pakistan. Potato Virus X (PVX) is in the list of the top ten economically damaging plant viruses in the world. Thirty three varieties/advanced lines of potato were screened against Potato Virus A (PVA), Potato Leaf Roll Virus (PLRV), Potato Virus M (PVM), Potato Virus S (PVS) and PVX. CIP-72-Y-3 was infected with PVA, PVM, PVS and PVX while Sahiwal-3, 34-1-Y, Sahiwal-4, 34-2-Y, Sahiwal-5, Sahiwal-6 and CIP-72-Y-4 showed reaction against PVA, PVS and PVX. 34-Y-3 found positive against PVA and PVX while PVM and PVX were confirmed in 34-4-X and CIP-72-Y-1. Azado-3, 34-6-X and 36-2 were positive with PLRV and PVM. 36-1, 34-S-1, 34-S-3-H and 42-1(Rusal Invary) were infected with PLRV and PVX while PVS and PVX were detected in Sahiwal-2, Azado-2, 42-2 (Rusal Invary) and CIP-72-Y-2. Eleven, one, nine, two, eight and two varieties/advanced lines of potato were highly resistance, highly susceptible, moderately susceptible, resistance, susceptible, against PVX respectively. Coat protein (CP) gene specific sense and antisense primes successfully amplified a 750 bp CP fragment of PVX in infected samples through Polymerase Chain Reaction (PCR) Assay.

During the year 2010-11 and 2011-12, disease incidence of Verticillium dahliae in Rawalpindi (Tax... more During the year 2010-11 and 2011-12, disease incidence of Verticillium dahliae in Rawalpindi (Taxila and Adyala) and Islamabad (National Agricultural Research Centre) was investigated in farmer’s potato fields. During the year 2010-11, maximum mean incidence was 24, 15 and 9% in Taxila, Adyala and NARC region respectively. Mean disease incidence increase 1% and 8% in Islamabad and Adyala while it was reduced by 3% in Taxila region respectively, during the second year of investigation. Over all mean disease incidence was increased by 2% comparison to disease incidence during second year. Maximum size of microsclerotia was recorded 63.9 µm in NARC while Taxila has smallest size of microsclerotia 35.7 µm. Colony was dark brown to black and conidiophores were phialides, erect and septate. Ovate-oblong and elliptical conidia were singly associated to end of terminal branches before falling away. Taxila and Adyala isolate showed virulent behavior and Islamabad isolates were found the least virulent on Cardinal and Coroda. Most suitable temperature, pH and culture media were 26 C, 7 and verticillim specific media for the growth of V. dahliae respectively.

Incidence of six virus diseases of Potato in Rawalpindi, Islamabad, Faisalabad and Sahiwal were i... more Incidence of six virus diseases of Potato in Rawalpindi, Islamabad, Faisalabad and Sahiwal were investigated in field samples. Enzyme Linked Immunosorbent Assay (ELISA) tests revealed that Potato virus Y (PVY) was most predominant virus followed by Potato virus X (PVX), Potato virus A (PVA), Potato virus S (PVS), Potato virus M (PVM) and Potato leaf roll virus (PLRV). During the year 2011-12, the average incidence of potato virus diseases in four locations was 52.3%. Single, double, triple, quadruple and quintuple infections were 41.89, 21.78, 16.2, 17.87 and 2.23% respectively. Chenopodium quinoa produced local chlorotic lesion against PVX, PVM and PVS. Systemic infection of PVX and no infection of PVM and PVS were observed on Nicotiana tabacum cv. Samsun.

World Journal of Biology and Biotechnology, 2020