67 research outputs found

    Effect of shade levels on production and quality of cordyline (Cordyline terminalis)

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    An investigation was carried out during 2013-14 to study the effect of different shade levels on the production and quality of cordyline (Cordyline terminalis Kunth.) under the subtropical condition of New Delhi, India. The effect of spectral control of light on physiology and vegetative development was evaluated at different crop growth stages. Shade nets did not only protect plants from high light intensities but also improved the vegetative growth, yield, vase life and quality of cordyline cut greens irrespective of shade level. Different shade levels modified microclimates, PAR, transmittance and canopy temperature. The shading improved plant characters like height, number of leaves, chlorophyll content, leaf area, fresh weight, harvest index and vase life. The plants grown under different shade levels showed improved photosynthetic activity and reduced transpiration rate. Plants grown under 50% shade level were taller, along with more number of leaves having longer petiole, chlorophyll content which can be attributed to higher photosynthetic rate, whereas harvest index and vase life was optimum. Overall, shade net with 50% shading was found best for commercial production of cordyline cut greens

    Are web corpora inferior? The Case of Czech and Slovak

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    Our paper describes an experiment aimed to assessment of lexical coverage in web corpora in comparison with the traditional ones for two closely related Slavic languages from the lexicographers’ perspective. The preliminary results show that web corpora should not be considered ― inferior, but rather ― different

    Genetic diversity and population structure of Fusarium fujikuroi causing Bakanae, an emerging disease of rice in India

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    Bakanae caused by Fusarium fujikuroi (Nirenberg), is emerging as a serious threat for rice (Oryza sativa. L.) cultivation in India. In this study, 63 isolates of Fusarium fujikuroi isolated from symptomatic diseased plants were characterized for their morphology, pathogenicity and molecular variability using universal rice primers (URP). Of the 12 URPs used in the study, 6 primers could produce polymorphic fragments in all the isolates. The URP 17R primer was highly polymorphic (100%), whereas, the URP 1F primer produced 75% polymorphic fragments. A dendrogram obtained from the combined analysis of 6 URP primers categorized the isolates into four clusters, where most of the isolates from Punjab and Haryana were clustered separately. Mating type of the population was identified based on MAT-1 and MAT-2 region universal primers for Gibberella fujikuroi. Among the 63 isolates, 18 (28.57%) were identified as MAT-1 and 45 (71.42%) as MAT-2. The effective population number for mating type was 89% of the total population. Since the distribution frequencies of both mating types were not equal in the Indian population of F. fujikuroi, it could conclude that majority of the multiplication of isolates under field conditions was through asexual reproduction. However, the presence of both mating types in F. fujikuroi indicates that the population is also capable of sexual reproduction. Therefore, it is important to develop cultivars with inbuilt resistance to bakanae disease, taking into consideration the factors such as environmental conditions and variability of the pathogen in the area of intended cultivation

    Novel 4,8-benzobisthiazole copolymers and their field-effect transistor and photovoltaic applications

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    We are grateful to the EPSRC for funding through grants C, EP/L012294/1, EP/L017008/1 and EP/L012200/1 and to the European Research Council for funding from Grant 321305. Supporting data are accessible from 10.15129/9b457e8c-12bc-4a3a-9af3-7f53474f4e5c.A series of copolymers containing the benzo[1,2-d:4,5-d′]bis(thiazole) (BBT) unit has been designed and synthesised with bisthienyl-diketopyrrolopyrrole (DPP), dithienopyrrole (DTP), benzothiadiazole (BT), benzodithiophene (BDT) or 4,4′-dialkoxybithiazole (BTz) comonomers. The resulting polymers possess a conjugation pathway that is orthogonal to the more usual substitution pathway through the 2,6-positions of the BBT unit, facilitating intramolecular non-covalent interactions between strategically placed heteroatoms of neighbouring monomer units. Such interactions enable a control over the degree of planarity through altering their number and strength, in turn allowing for tuning of the band gap. The resulting 4,8-BBT materials gave enhanced mobility in p-type organic field-effect transistors of up to 2.16 × 10-2 cm2 V-1 s-1 for pDPP2ThBBT and good solar cell performance of up to 4.45% power conversion efficiency for pBT2ThBBT.Publisher PDFPeer reviewe

    Genome-wide association study reveals novel genomic regions governing agronomic and grain quality traits and superior allelic combinations for Basmati rice improvement

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    BackgroundBasmati is a speciality segment in the rice genepool characterised by explicit grain quality. For the want of suitable populations, genome-wide association study (GWAS) in Basmati rice has not been attempted.MaterialsTo address this gap, we have performed a GWAS on a panel of 172 elite Basmati multiparent population comprising of potential restorers and maintainers. Phenotypic data was generated for various agronomic and grain quality traits across seven different environments during two consecutive crop seasons. Based on the observed phenotypic variation, three agronomic traits namely, days to fifty per cent flowering, plant height and panicle length, and three grain quality traits namely, kernel length before cooking, length breadth ratio and kernel length after cooking were subjected to GWAS. Genotyped with 80K SNP array, the population was subjected to principal component analysis to stratify the underlying substructure and subjected to the association analysis using Bayesian-information and Linkage-disequilibrium Iteratively Nested Keyway (BLINK) model.ResultsWe identified 32 unique MTAs including 11 robust MTAs for the agronomic traits and 25 unique MTAs including two robust MTAs for the grain quality traits. Six out of 13 robust MTAs were novel. By genome annotation, six candidate genes associated with the robust MTAs were identified. Further analysis of the allelic combinations of the robust MTAs enabled the identification of superior allelic combinations in the population. This information was utilized in selecting 77 elite Basmati rice genotypes from the panel.ConclusionThis is the first ever GWAS study in Basmati rice which could generate valuable information usable for further breeding through marker assisted selection, including enhancing of heterosis

    Fine mapping of qBK1.2, a major QTL governing resistance to bakanae disease in rice

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    Bakanae disease caused by Fusarium fujikuroi is an emerging disease of rice causing losses in all rice-growing regions around the world. A BC2F2 population was developed by backcrossing the recurrent parent Pusa Basmati 1121 (PB1121) with the recombinant inbred line RIL28, which harbors a major quantitative trait locus (QTL) governing resistance to bakanae, qBK1.2. MassARRAY-based single-nucleotide polymorphism (SNP) assays targeting the genomic region of qBK1.2 helped in fine mapping the QTL to a region of 130 kb between the SNP markers rs3164311 and rs3295562 using 24 recombinants. In-silico mining of the fine-mapped region identified 11 putative candidate genes with functions related to defense. The expression analysis identified two significantly differentially expressed genes, that is, LOC_Os01g06750 and LOC_Os01g06870, between the susceptible genotype PB1121 and the resistant genotypes Pusa1342 and R-NIL4. Furthermore, the SNPs identified in LOC_Os01g06750 produced minor substitutions of amino acids with no major effect on the resistance-related functional motifs. However, LOC_Os01g06870 had 21 amino acid substitutions, which led to the creation of the leucine-rich repeat (LRR) domain in the resistant genotype Pusa1342, thereby making it a potential candidate underlying the major bakanae-resistant QTL qBK1.2. The markers used in the fine mapping program are of immense utility in marker-assisted breeding for bakanae resistance in rice

    Identification of a major QTL, Parth6.1 associated with parthenocarpic fruit development in slicing cucumber genotype, Pusa Parthenocarpic Cucumber-6

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    Parthenocarpy is an extremely important trait that revolutionized the worldwide cultivation of cucumber under protected conditions. Pusa Parthenocarpic Cucumber-6 (PPC-6) is one of the important commercially cultivated varieties under protected conditions in India. Understanding the genetics of parthenocarpy, molecular mapping and the development of molecular markers closely associated with the trait will facilitate the introgression of parthenocarpic traits into non-conventional germplasm and elite varieties. The F1, F2 and back-crosses progenies with a non-parthenocarpic genotype, Pusa Uday indicated a single incomplete dominant gene controlling parthenocarpy in PPC-6. QTL-seq comprising of the early parthenocarpy and non-parthenocarpic bulks along with the parental lines identified two major genomic regions, one each in chromosome 3 and chromosome 6 spanning over a region of 2.7 Mb and 7.8 Mb, respectively. Conventional mapping using F2:3 population also identified two QTLs, Parth6.1 and Parth6.2 in chromosome 6 which indicated the presence of a major effect QTL in chromosome 6 determining parthenocarpy in PPC-6. The flanking markers, SSR01148 and SSR 01012 for Parth6.1 locus and SSR10476 and SSR 19174 for Parth6.2 locus were identified and can be used for introgression of parthenocarpy through the marker-assisted back-crossing programme. Functional annotation of the QTL-region identified two major genes, Csa_6G396640 and Csa_6G405890 designated as probable indole-3-pyruvate monooxygenase YUCCA11 and Auxin response factor 16, respectively associated with auxin biosynthesis as potential candidate genes. Csa_6G396640 showed only one insertion at position 2179 in the non-parthenocarpic parent. In the case of Csa_6G405890, more variations were observed between the two parents in the form of SNPs and InDels. The study provides insight about genomic regions, closely associated markers and possible candidate genes associated with parthenocarpy in PPC-6 which will be instrumental for functional genomics study and better understanding of parthenocarpy in cucumber

    Salmonella enterica Serovar Typhimurium Lacking hfq Gene Confers Protective Immunity against Murine Typhoid

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    Salmonella enterica is an important enteric pathogen and its various serovars are involved in causing both systemic and intestinal diseases in humans and domestic animals. The emergence of multidrug-resistant strains of Salmonella leading to increased morbidity and mortality has further complicated its management. Live attenuated vaccines have been proven superior over killed or subunit vaccines due to their ability to induce protective immunity. Of the various strategies used for the generation of live attenuated vaccine strains, focus has gradually shifted towards manipulation of virulence regulator genes. Hfq is a RNA chaperon which mediates the binding of small RNAs to the mRNA and assists in post-transcriptional gene regulation in bacteria. In this study, we evaluated the efficacy of the Salmonella Typhimurium Δhfq strain as a candidate for live oral vaccine in murine model of typhoid fever. Salmonella hfq deletion mutant is highly attenuated in cell culture and animal model implying a significant role of Hfq in bacterial virulence. Oral immunization with the Salmonella hfq deletion mutant efficiently protects mice against subsequent oral challenge with virulent strain of Salmonella Typhimurium. Moreover, protection was induced upon both multiple as well as single dose of immunizations. The vaccine strain appears to be safe for use in pregnant mice and the protection is mediated by the increase in the number of CD4+ T lymphocytes upon vaccination. The levels of serum IgG and secretory-IgA in intestinal washes specific to lipopolysaccharide and outer membrane protein were significantly increased upon vaccination. Furthermore, hfq deletion mutant showed enhanced antigen presentation by dendritic cells compared to the wild type strain. Taken together, the studies in murine immunization model suggest that the Salmonella hfq deletion mutant can be a novel live oral vaccine candidate
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