1,549 research outputs found

    Breeding tomatoes suitable for processing with triple disease resistance to tomato leaf curl disease, bacterial wilt and early blight

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    India is the second largest producer of tomato with 11 per cent global share and cultivated on an estimated area of 0.76 million hectares with productivity of 24 tonnes per hectare. Less than 1% of the produce is processed when compared to 26% in other major producing countries. Of the estimated more than 41 million tonnes of tomato processed globally, only 130,000 tonnes were processed in India and domestic demand for processed tomato products is expanding at an estimated 30% annually. At present traditional fresh market tomato cultivars are being processed though such cultivars are unsuitable for processing. Processors in India are looking for high yielding tomato cultivars with high total soluble solids (5-6 º Brix), acidity not less than 0.4%, pH less than 4.5 and uniform red colour with a/b colour value of at least 2. In addition, firm fruited tomato cultivars with joint less pedicel (j2) which facilitate mechanical harvesting or rapid hand picking. ICAR-Indian Institute of Horticultural Research has recently developed two high yielding F1 hybrids in tomato viz: Arka Apeksha and Arka Vishesh suitable for processing. On evaluation for three years, both the hybrids recorded good level of total soluble solids (4.5-5º Brix) and colour value of 2. Further, both the hybrids had high yield potential (80-90 tonnes / hectare) with triple disease resistance to tomato leaf curl disease, bacterial wilt and early blight. Arka Apeksha and Arka Vishesh were also bred with jointless pedicel making them suitable for mechanical harvesting. Our experimental studies on vine storability revealed that all the fruits were intact on plants even 110 days after transplanting in the main field facilitating once over harvest

    Synthesis, characterization and DNA cleavage activity of nickel(II) adducts with aromatic heterocyclic bases

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    Mixed ligand complexes of nickel(II) with 2,4-dihydroxyaceto-phenone oxime (DAPO) and 2,4-dihydroxybenzophenone oxime (DBPO) as primary ligands, and pyridine (Py) and imidazole (Im) as secondary ligands were synthesized and characterized by molar conductivity, magnetic moments measurements, as well as by electronic, IR, and 1H-NMR spectroscopy. Electrochemical studies were performed by cyclic voltammetry. The active signals are assignable to the NiIII/II and NiII/I redox couples. The binding interactions between the metal complexes and calf thymus DNA were investigated by absorption and thermal denaturation. The cleavage activity of the complexes was determined using double-stranded pBR322 circular plasmid DNA by gel electrophoresis. All complexes showed increased nuclease activity in the presence of the oxidant H2O2. The nuclease activities of mixed ligand complexes were compared with those of the parent copper(II) complexes

    Biological relationship of Bean common mosaic virus (BCMV) infecting cowpea with leguminous plant species

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    Bean common mosaic virus (BCMV) associated with cowpea mechanically inoculated to different legumi-nous plants. Out of nineteen including cowpea Var.C-152, the virus was easily transferred to ten different legumi-nous hosts. All other hosts assessed for the presence of BCMV were found to be uninfected. The number of days taken for symptom expression and symptoms were varied within plant species. Pole bean expressed mosaic symp-tom after long incubation period (15-18 days) whereas, shorter incubation period was observed in common bean and rice bean (7- 10 days). BCMV produced chlorosis, mosaic, leaf distortion, puckering, vein banding, vein clearing and vein netting on cowpea(C-152). A typical virus symptom, mosaic was observed in green gram, common bean, lime bean, rice bean and yard long bean, whereas, leaf rolling and leaf distortion was observed in black gram, pole bean and snap bean. The virus-host relationship was confirmed by back inoculation test to C. amaranticolor. Further symptomatic plants were subjected for Reverse Transcriptase polymerase chain reaction (RT-PCR) for molecular confirmation using BCMV coat protein (CP) specific primer pair. A PCR fragment size of 439bp was amplified for the symptomatic plants. The results generated indicated the ability of a plant to support virus expression and host speci-ficity of BMCV within the leguminous plant species

    Assessment of crop loss in Arabica coffee due to white stem borer, Xylotrechus quadripes Chevrolat (Coleoptera: Cerambycidae) infestation

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    The coffee white stem borer (CWSB) is the most dreaded pest of Arabica coffee in India. Due to the concealed nature of this pest, the management measures are difficult and require the timely implementation of control measures. The recommended practices for the management of CWSB mainly targets on eggs and early instar larvae, apart from tracing and uprooting of infested plants before the commencement of flight periods (April-May and Oct-Dec). In general, youngArabica coffee plants infested by CWSB die within a year, whereas aged plants withstand the attack for few more years. However, such plants become less productive, susceptible to diseases and also serve as inoculum for further spreading of the infestation. A study was undertaken to assess the crop loss due to CWSB infestation on established Arabica plantation in Tamil Nadu. The result indicated a significant difference between healthy and infested plants and the crop loss was to the tune of 17.7 per cent. Further, quantitative data on out-turn percentages recorded at different stages of coffee processing (right from harvesting of fruits to marketable green coffee bean) are discussed in this paper

    Resistance to late leaf spot and rust diseases in ICRISAT’s mini core collection of peanut (Arachis hypogaea L.)

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    Late leaf spot (LLS) (Phaeoisariopsis personata) and rust (Puccinia arachidis) are major foliar diseases of peanut causing significant losses worldwide. Identification and infusion of resistance into peanut cultivars is important in the management of these diseases. The present study therefore aimed at screening the peanut mini core collection to identify potential sources of resistance to these diseases. Two separate field experiments were conducted for screening LLS and rust under artificial epiphytotic conditions during rainy seasons of 2012 and 2013 at ICRISAT, Patancheru, India. The trials were laid in a randomized complete block design on beds with three replications. Data on LLS and rust disease severities were collected using 1 to 9 scales at 75, 90 and 105 days after sowing (DAS), and pod yields were recorded at harvest. Results indicate significant variations among accessions for LLS and rust resistance. Mean of 2 years study revealed that 53 accessions were moderately resistant (MR), 86 accessions were susceptible (S) and 45 accessions were highly susceptible (HS) to LLS. For rust disease, 10 accessions were resistant (R), 115 accessions were with ‘MR’ reaction and 59 accessions with susceptible (S) reaction. Six superior accessions in terms of combined disease resistance and yield (ICGs 4389, 6993, 11426, 4746, 6022, 11088) were selected and the disease progress curves, for each, were generated. Highest yields were recorded with ICG 11426 in LLS and rust plots. Overall, our results indicate that these six accessions can be potential sources of LLS and rust resistance

    Ultrastructural studies on the interaction between Bacillus subtilis MBI 600 (Integral®) and the rice sheath blight pathogen, Rhizoctonia solani

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    The present study evaluated interactions of the biological control agent Bacillus subtilisstrain MBI 600 (Integral®) and Rhizoctonia solani, the rice sheath blight pathogen, through scanning electron microscopy (SEM). Ultrastructural effects related to antibiosis were studied by dual culture of B. subtilis (MBI 600) and R. solani on potato dextrose agar (PDA) plates. Hyphal growth near the inhibition zone was processed. To study the effects of hyperparasitism on fungal ultrastructure, Integral was sprayed on R. solani mycelia and observations were made three days later. Interactions of B. subtilis (MBI 600) and R.solani in planta were determined by spraying detached rice leaves with B. subtilis (MBI 600) and then inoculating with sclerotia of R. solani. In addition, sclerotia were dipped in Integral for 24 h, and cut sections were then observed. Overall the results indicate that B. subtilis (MBI 600) caused loss of structural integrity, shriveling, abnormal coiling, and lysis of the R. solani hyphae due to antibiosis and hyperparasitism in dual culture assays. On rice leaves, B. subtilis (MBI 600) also caused abnormal coiling, shriveling, and break down of hyphae. Sclerotia of R. solani dipped in Integral resulted in colonization of B. subtilis(MBI 600), maceration, and fragmentation of inner walls. Our results suggest that B. subtilis (MBI 600) from the product Integral was highly effective in suppressing R. solani

    The Minimal CFL-Nuclear Interface

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    At nuclear matter density, electrically neutral strongly interacting matter in weak equilibrium is made of neutrons, protons and electrons. At sufficiently high density, such matter is made of up, down and strange quarks in the color-flavor locked phase, with no electrons. As a function of increasing density (or, perhaps, increasing depth in a compact star) other phases may intervene between these two phases which are guaranteed to be present. The simplest possibility, however, is a single first order phase transition between CFL and nuclear matter. Such a transition, in space, could take place either through a mixed phase region or at a single sharp interface with electron-free CFL and electron-rich nuclear matter in stable contact. Here we construct a model for such an interface. It is characterized by a region of separated charge, similar to an inversion layer at a metal-insulator boundary. On the CFL side, the charged boundary layer is dominated by a condensate of negative kaons. We then consider the energetics of the mixed phase alternative. We find that the mixed phase will occur only if the nuclear-CFL surface tension is significantly smaller than dimensional analysis would indicate.Comment: 30 pages, 7 figure
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