22 research outputs found

    Pyramiding and evaluation of segregating lines containing lectin and protease inhibitor genes for aphid resistance in Brassica juncea

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    Aphids are one of the most devastating pests, affecting the potential yield and quality ofBrassica juncea. In the current study, we have attempted to pyramid two transgenic lines containing chickpea lectin (CHPL, P1) and urdbean protease inhibitor (UPI, P2) in each under the phloem specific rolC promoter, through conventional breeding approach. In the derived F2 population, both lectin and protease inhibitor genes were segregating in a 9:3:3:1 ratio (p-value: 0.81), indicative of a single copy of the transgenes in the parents. Furthermore, the parental, as well as pyramided progenies were evaluated for their potential resistance to aphids in terms of mortality and natality. The lines containing both the transgenes were found to be superior over single gene transgenics as a higher mortality rate (96%) was found in F2on the 9th day as compared to single gene transgenics (86% and 80% in P1 and P2 respectively). A significant decrease in the number of nymphs was observed in P1 and P2 but most in F2 plants as almost 43, 32.08, and 107.5 times decrease in the number of nymphs was found in P1, P2, and F2 individuals over control. Expression profiling was done to see if there was any impact of gene pyramiding on the expression pattern of both transgenes before and after aphid treatment, and no significant changes were observed, indicating constitutive expression of transgenes in pyramided lines also. In conclusion, pyramided lines were found to be promising and were superior for aphid resistance

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    Not AvailableGlobally, maize is an important cereal food crop with the highest production and productivity. Among the biotic constraints that limit the productivity of maize, the recent invasion of fall armyworm (FAW) in India is a concern. The first line of strategy available for FAW management is to evaluate and exploit resistant genotypes for inclusion in an IPM schedule. Screening for resistant maize genotypes against FAW is in its infancy in India, considering its recent occurrence in the country. The present work attempts to optimize screening techniques suited to Indian conditions, which involve the description of leaf damage rating (LDR) by comparing injury levels among maize genotypes and to validate the result obtained from the optimized screening technique by identification of lines potentially resistant to FAW under artificial infestation. Exposure to 20 neonate FAW larvae at the V 5 phenological stage coupled with the adoption of LDR on a 1–9 scale aided in preliminary characterize maize rize maize genotypes as potentially resistant, moderately resistant, and susceptible. The LDR varies with genotype, neonate counts, and days after infestation. The genotypes, viz., DMRE 63, DML-163-1, CML 71, CML 141, CML 337, CML 346, and wild ancestor Zea mays ssp. parviglumis recorded lower LDR ratings against FAW and can be exploited for resistance breeding in maize.ICAR-NAS

    Endophytic establishment of native Bacillus thuringiensis strain in maize plants and its efficacy against Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae)

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    Abstract Background Bacillus thuringiensis (Bt) is known as the most successful microbial insecticide worldwide used against lepidopteran insect pests in agriculture. Native Bacillus isolate VKK5 showing insecticidal activity against Spodoptera frugiperda (FAW) (J.E. Smith) (Lepidoptera: Noctuidae) was characterized as B. thuringiensis (BtVKK5) on a morphological and molecular basis. Recent research has shown that Bt can be established as an endophytic organism for controlling insect pests. The present work aimed at assessing the colonization of BtVKK5 as an endophyte in five maize cultivars by seed treatment (ST), soil drenching (SD), foliar application (FA) and combination of all methods (ST + SD + FA) and its bioefficacy against neonates of FAW. Results Establishment of inoculated BtVKK5 as endophytes in five maize cultivars, viz. Pusa HQPM7 Improved, Pusa Jawahar Hybrid Maize 1, Pusa Vivek Hybrid 27 Improved (PVH27I), Pusa HQPM5 Improved and DMRH 1301, was confirmed by re-isolating from the leaves of the plant on ampicillin-selected agar plates. Estimation of colony-forming units per gram of leaf showed that there was a significant difference in colonization of the Bt strain among maize cultivars by different inoculation methods. The colonies were further substantiated by the amplification of cry1A and cry1E genes. Bioefficacy studies showed the highest mortality (50%) in the ST + FA + SD inoculation method, followed by ST (40%) in PVH27I. Moreover, growth inhibition was observed in survived larvae on inoculated plants vis-a-vis control. Conclusion Establishment of Bt strain as an endophyte in maize plants, complemented with insecticidal activity, could possibly lead to an innovative approach to the management of S. frugiperda and other borers

    CFD analysis of turboprop engine oil cooler duct for best rate of climb condition

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    Turboprop engines are widely used in commuter category airplanes. Aircraft Design bureaus routinely conduct the flight tests to confirm the performance of the system. The lubrication system of the engine is designed to provide a constant supply of clean lubrication oil to the engine bearings, the reduction gears, the torque-meter, the propeller and the accessory gearbox. The oil lubricates, cools and also conducts foreign material to the oil filter where it is removed from further circulation. Thus a means of cooling the engine oil must be provided and a suitable oil cooler (OC) and ducting system was selected and designed for this purpose. In this context, it is relevant to study and analyse behaviour of the engine oil cooler system before commencing actual flight tests. In this paper, the performance of the oil cooler duct with twin flush NACA inlet housed inside the nacelle has been studied for aircraft best rate of climb (ROC) condition using RANS based SST K-omega model by commercial software ANSYS Fluent 13.0. From the CFD analysis results, it is found that the mass flow rate captured and pressure drop across the oil cooler for the best ROC condition is meeting the oil cooler manufacturer requirements thus, the engine oil temperature is maintained within prescribed limits

    <span style="font-size:11.0pt;font-family: "Times New Roman";mso-fareast-font-family:"Times New Roman";mso-bidi-font-family: Mangal;mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language: HI" lang="EN-GB">Isolation and characterization of Lepidoptera specific <i style="mso-bidi-font-style: normal">Bacillus thuringiensis</i><span style="mso-bidi-font-style:italic"> strains predominantly from north-eastern states of India</span></span>

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    431-451<span style="font-size:11.0pt;font-family: " times="" new="" roman";mso-fareast-font-family:"times="" roman";mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" hi"="" lang="EN-GB">Both, the tobacco caterpillar Spodoptera litura (Fabricius) and the cotton bollworm <i style="mso-bidi-font-style: normal">Helicoverpa armigera (Hübner), are serious polyphagous pests causing considerable loss to crops. Indiscriminate use of chemical pesticides for controlling them has rather resulted in their resistance development. Microbial pesticides, Bacillus thuringiensis in particular, play an important role in pest management. Here, we <span style="mso-bidi-font-weight: bold">isolated Bacillus thuringiensis-<span style="mso-bidi-font-style: italic">like bacteria from the soil samples primarily collected from North East region of India along with some states viz., Haryana, Punjab, Maharashtra, West Bengal and Uttarakhand and studied their toxicity against the above two insect pests at 10 µg/g <span style="mso-bidi-font-weight: bold">along with standard strain B. thuringiensis subsp. kurstaki HD-1 and at 1 µg/g Pseudomonas fluorescens based MVPII expressing Cry1Ac toxin and AUG-5. Isolates AUG-5 and GTG-7 proved toxic to more than 75% larvae on the 4th as well as 7th day of the treatment of the neonates of H. armigera. The AUG-5 isolate was also effective against S. litura. Ten effective isolates (AUG-5, GTG-4, GTG-7, GTG-9, GTG-42, GTG-64, GTG-70, GTG-3S, GTG-4S and GTG-6S) were characterized using biochemical and 16S rDNA analysis. Nearly, all the isolates tested positive for utilizing monosaccharides. All selected B. thuringiensis isolates showed resistance to ampicillin and co-trimoxazole except AUG-5 to co-trimoxazole. AUG-5 and GTG-7 were highly toxic to both insects, and possessed cry1, cry1A and <i style="mso-bidi-font-style: normal">cry2 genes. These isolates AUG-5 and GTG-7 also contained high Cry1Ac (104.8 and 88.32 ng/mg) and Cry2Ab (3792 and 1305.9 ng/mg), respectively in their spore-crystal complex. Both, AUG-5 and GTG-7 isolates, could be considered for further development as bioinsecticides. The present study has established the diversity and richness of B. thuringiensis-like isolates in soils collected from north-eastern region of India.</span

    Entry modes and key local practices of international super-deluxe hotel chains in South Korea

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    In our study, we reviewed business practices adopted by global hotel chains, gathered relevant information from secondary sources, and conducted interviews and surveys with hotels and various related organisations in Singapore and South Korea.Master of Business Administration (Marketing

    Differential Activities of Antioxidant Enzymes, Superoxide Dismutase, Peroxidase, and Catalase vis-à-vis Phosphine Resistance in Field Populations of Lesser Grain Borer (<i>Rhyzopertha dominica</i>) from India

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    Susceptibility to phosphine was compared in 15 populations of lesser grain borer (Rhyzopertha dominica) collected from grain storage godowns across India. A high level of resistance to phosphine was noticed in R. dominica collected from northern India compared to those collected from northeastern regions of India. The median lethal concentration values varied from 0.024 mg/L to 1.991 mg/L, with 1.63 to 82.96-fold resistance compared to laboratory susceptible checks. Antioxidant enzymes have been reported to negate the reactive oxygen species generated upon encountering the fumigant phosphine. Distinct differences in the activity of antioxidant enzymes were noticed in the field populations exposed to phosphine. Peroxidase activity varied between 1.28 and 336.8 nmol H2O2 reduced/min/mg protein. The superoxide dismutase inhibition rate was between 81.29 and 99.66%, and catalase activity varied between 6.28 and 320.13 nmol H2O2 reduced/min/mg protein. The findings of our investigation show that the activities of peroxidase and superoxide dismutase are positively linked (p 2•−, H2O2,•OH) associated with tolerance to phosphine in R. dominica.</i

    In Vitro and In Vivo Studies of Heraclenol as a Novel Bacterial Histidine Biosynthesis Inhibitor against Invasive and Biofilm-Forming Uropathogenic <i>Escherichia coli</i>

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    Globally, urinary tract infections (UTIs) are one of the most frequent bacterial infections. Uropathogenic Escherichia coli (UPEC) are the predominant etiological agents causing community and healthcare-associated UTIs. Biofilm formation is an important pathogenetic mechanism of UPEC responsible for chronic and recurrent infections. The development of high levels of antimicrobial resistance (AMR) among UPEC has complicated therapeutic management. Newer antimicrobial agents are needed to tackle the increasing trend of AMR and inhibit biofilms. Heraclenol is a natural furocoumarin compound that inhibits histidine biosynthesis selectively. In this study, for the first time, we have demonstrated the antimicrobial and antibiofilm activity of heraclenol against UPEC. The drug reduced the bacterial load in the murine catheter UTI model by ≥4 logs. The drug effectively reduced bacterial loads in kidney, bladder, and urine samples. On histopathological examination, heraclenol treatment showed a reversal of inflammatory changes in the bladder and kidney tissues. It reduced the biofilm formation by 70%. The MIC value of heraclenol was observed to be high (1024 µg/mL), though the drug at MIC concentration did not have significant cytotoxicity on the Vero cell line. Further molecular docking revealed that heraclenol binds to the active site of the HisC, thereby preventing its activation by native substrate, which might be responsible for its antibacterial and antibiofilm activity. Since the high MIC of heraclenol is not achievable clinically in human tissues, further chemical modifications will be required to lower the drug’s MIC value and increase its potency. Alternatively, its synergistic action with other antimicrobials may also be studied
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