Dixit S.,CSIR - Central Electrochemical Research Institute |
Dixit S.,Academy of Scientific and Innovative Research AcSIR |
Upadhyay S.K.,CSIR - Central Electrochemical Research Institute |
Upadhyay S.K.,National Agri Food Biotechnology Institute |
And 6 more authors.
PLoS ONE | Year: 2013
Plants naturally emit methanol as volatile organic compound. Methanol is toxic to insect pests; but the quantity produced by most of the plants is not enough to protect them against invading insect pests. In the present study, we demonstrated that the over-expression of pectin methylesterase, derived from Arabidopsis thaliana and Aspergillus niger, in transgenic tobacco plants enhances methanol production and resistance to polyphagous insect pests. Methanol content in the leaves of transgenic plants was measured using proton nuclear spectroscopy (1H NMR) and spectra showed up to 16 fold higher methanol as compared to control wild type (WT) plants. A maximum of 100 and 85% mortality in chewing insects Helicoverpa armigera and Spodoptera litura larvae was observed, respectively when fed on transgenic plants leaves. The surviving larvae showed less feeding, severe growth retardation and could not develop into pupae. In-planta bioassay on transgenic lines showed up to 99 and 75% reduction in the population multiplication of plant sap sucking pests Myzus persicae (aphid) and Bemisia tabaci (whitefly), respectively. Most of the phenotypic characters of transgenic plants were similar to WT plants. Confocal microscopy showed no deformities in cellular integrity, structure and density of stomata and trichomes of transgenic plants compared to WT. Pollen germination and tube formation was also not affected in transgenic plants. Cell wall enzyme transcript levels were comparable with WT. This study demonstrated for the first time that methanol emission can be utilized for imparting broad range insect resistance in plants. Copyright: © 2013 Dixit et al.
Babu S.C.,International Food Policy Research Institute |
Huang J.,Chinese Academy of Sciences |
Venkatesh P.P.,India Agricultural Research Institute |
Zhang Y.,Chinese Academy of Agricultural Sciences
China Agricultural Economic Review | Year: 2015
Purpose - There is growing interest from the global development community in the role of agricultural research and extension (AR&E) systems to achieve development targets. Despite this interest, many smallholders in developing countries continue to lack access to updated agricultural information and reliable services. In an effort to increase the effectiveness, impact, and reach of AR&E programs, many governments have attempted to reform their national systems. The paper aims to discuss these issues. Design/methodology/approach - This paper systematically compares the systems and reforms of AR&E in China and India in order to draw out lessons applicable to developing countries. This paper first reviews the existing literature on AR&E systems and their role in agricultural and economic development. The authors then provide a detailed review and comparative analysis of the reforms and approaches implemented in the AR&E systems of China and India. The authors apply this comparative analysis to draw out lessons that can be applied to inform the reformation of AR&R systems in developing countries. Findings - The authors find that although both countries face similar agricultural development challenges, each took a different approach in the reformation of AR&E to address these challenges. Each country's approaches had different impacts on the effectiveness of the system. Lessons from the reformation of the AR&E systems in China and India can be used to inform and improve the impact of AR&E in developing countries. Originality/value - The paper examines two systems together using a set of common indicators and factors. The paper's value comes from its usefulness in informing future AR&E reforms in other developing countries in order to increase the impact of these reforms on development outcomes. © Emerald Group Publishing Limited.
Kumar V.,India Agricultural Research Institute |
Kumar V.,Seed Production Unit |
Tomar B.S.,India Agricultural Research Institute |
Singh B.,India Agricultural Research Institute |
Kumar S.,India Agricultural Research Institute
Indian Journal of Agricultural Sciences | Year: 2014
An investigation was carried out, to study the effect of post-harvest ripening and drying methods on the seed quality in pumpkin cv Pusa Hybrid 1, during summer 2008 and 2009 at Seed Production Unit, IARI, New Delhi. After harvesting, the fruits were allowed for post-harvest ripening (PHR) of zero days (P0), 10 days (P1) and 20 days (P2) and seeds obtained from each of the PHR treatments were subjected to three methods of drying, viz. shade drying (D1), sun drying (D2) and mechanical drying (D3). The results showed that seed obtained from 20 days PHR followed by shade drying (P2D1) had given superior quality seed with respect to germination (94. 33 %), seedling length (34. 30 cm), vigour index - I (3236. 52) and electrical conductivity (17. 30 m mhos/cm/g) followed by P2D3(20 days PHR and mechanical drying), while germination (%) was significantly lower in PoD2during storage. In all treatments the seeds stored for 12 months showed maximum germination followed by reduction after eighteen months of storage. The germination percentage was maintained above the Indian minimum seed certification standards (IMSCS) of 60% up to eighteen months of storage in all treatments.
Gupta B.,Indian Institute of Technology Roorkee |
Rani M.,Indian Institute of Technology Roorkee |
Kumar R.,Indian Institute of Technology Roorkee |
Dureja P.,India Agricultural Research Institute
Chemosphere | Year: 2011
The widespread occurrence of pesticide residues in different agricultural and food commodities has raised concern among the environmentalists and food chemists. In order to keep a proper track of these materials, studies on their decay profiles in the various segments of ecosystem under varying environmental conditions are needed. In view of this, the metabolites of quinalphos in water and soil under controlled conditions and in plants, namely tomato and radish in field conditions have been analysed and possible pathways suggested. In order to follow the decay of the pesticide, an HPLC procedure has been developed. Studies conducted in water at different temperatures, pH and organic content reveal that the persistence of the pesticide decreases with the increase in all the three variables. In the three different types of soils studied, the effect of pH is more or less apparent on a similar line. On an average a faster decay is observed in the case of plants than in water and soil. The decay profiles in all these cases follow first order kinetics. The metabolites were identified by GC-MS. The investigations reflect that degradation occurs through hydrolysis, S-oxidation, dealkylation and thiono-thiol rearrangement. The pathways seem to be complex and different metabolites were observed with the change in the matrix. Quinalphos oxon, O-ethyl-O-quinoxalin-2-yl phosphoric acid, 2-hydroxy quinoxaline and quinoxaline-2-thiol were observed in all the matrices. Results further indicate that the metabolites, 2-hydroxy quinoxaline and oxon, which are more toxic than parent compound, persist for a longer time. © 2011 Elsevier Ltd.
Veeranna D.,India Agricultural Research Institute |
Mittal A.,India Agricultural Research Institute |
Rajashekhar M.,India Agricultural Research Institute |
Kalia V.K.,India Agricultural Research Institute
Biopesticides International | Year: 2015
Acetate selection procedure was used to screen eight samples of dust obtain after sieving the wheat and sweepings of waste stored product samples from seven different warehouses. A total of 1275 bacterial colonies were observed, of that 83 (6.5%) colonies belonged to Bacillus spp. All the warehouse samples were positive for Bacillus thuringiensis (Bt), however, overall Br index for these samples was 0.019. Further the isolated Bt strains were screened for their toxicity at single concentration of 10 μg/g of diet against a storage coleopteran pest, Tribolium castaneum and 2 polyphagous lepidopteran pests, Helicoverpa armigera and Spodoptera litura. Toxicity of native Bt strains was found to be variable against neonates of lepidopterans (23.3-50% mortality) as well as neonates and adults (23.3-63.3%) of T. casianeum. The data suggests that these Bt strains were less toxic to neonates of S. litura and H. armigera (up to 36% mortality) compared to T. castaneum (> 50% mortality). Six Bt strains showing more toxicity against T. castaneum indicates the coleopteran specificity of the toxins and need further characterization and development as bio-insecticides against coleopteran pests.