7,673 research outputs found
Collection, Characterization, Maintenance, Evaluation and Utilization of Castor Germplasm
No full textCastor genetic resources
Germplasm augmentation: Two accessions collected from Sundarban, West Bengal, 56 accessions received from NBPGR, New Delhi and 215 accessions supplied by AICRP (Castor) Mandor centre were added to the repository.
Characterization and evaluation: Seventy two fresh collections were characterized for 23 morphological descriptors. The same were evaluated for 19 quantitative traits under rainfed condition. Considerable variation was observed for different quantitative traits.
Supply of germplasm: Total 990 accessions were supplied to various centres for multilocation yield evaluation and screening against diseases and insect pests. In addition, 178 accessions were supplied for research purpose to various castor researchers in the country.
Germplasm multiplication and documentation: A total of 3144 accessions including 241 accessions supplied by NBPGR, New Delhi, 165 of castor core and 2738 accessions of DOR castor repository were multiplied. Passport information and data on morphological and quantitative traits of 72 fresh accessions were documented.
Castor germplasm field day: A castor germplasm field day was conducted on 4 November 2011. Twenty five castor researchers participated in the field day. On-farm performance of 3216 castor accessions, which are resistant to wilt, root rot, nematode, jassids, whitefly and leafminer, multiple resistance to wilt, root rot and nematode, tolerance to Botrytis; non-VP-1 pistillate selections, distinct morphotypes, fresh collections and accessions possessing promising yield traits, was demonstrated during the field day.
Castor core: Castor core comprising 165 accessions was characterized for 23 morphological descriptors and evaluated for 15 quantitative traits. Seeds of 165 accessions were multiplied.
Pistillate selections derived from germplasm: Forty four derivatives of nine non-TSP-10R pistillate selections showed stable pistillatness up to higher order spikes. These were maintained and multiplied.
Sources of resistance against diseases and insect pests
Wilt: Resistance to wilt was confirmed in seven accessions viz., RG1221, RG1354, RG2430, RG 3016, RG 2800, RG 3093 and RG 3105 using root-dip inoculation method. Nineteen accessions were found free from wilt in wilt sick plot while 10 had less than 20% infection.
Botrytis grey mold: Ten accessions (RG 26, RG 1139, RG 1759, RG 1963, RG 2759, RG 2810, RG 3216, RG 3309, RG 3311, RG 3383) exhibited resistant reaction (<10% capsule infection) against grey mold under artificial epiphytotic conditions in field.
Nematode: Thirty accessions exhibited moderate resistance (11-20 average number of egg masses/root system) against nematode under artificial inoculation conditions in glasshouse.
Leafhopper: Four accessions viz., RG 2661, RG 2468, RG 1445, and RG 3067 confirmed resistant reaction (0 hopper burn grade on 0-4 scale) against leafhopper in the third consecutive year while three accessions (RG 2499, RG 565, RG 220) showed moderate resistance reaction.
Capsule borer: One accession RG 2786 exhibited moderate resistance to capsule borer
Response of castor (
No full textThere is limited information on the appropriate agronomic practices for castor in the humid tropics. This study evaluated the effects of organic fertilizer (OF) and sowing date (SD) on the agronomic performance of castor during late cropping season (June − Dec.) of 2021 and 2022 at the Institute of Food Security, Environmental Resources and Agricultural Research, Abeokuta, Nigeria. Two factors: OF − control and organic fertilizer (main plot) and SD − eight sowing dates (SD1-SD8 i.e., from June 18 to August 5) at 7-day intervals (sub plot) were laid in a split-plot arrangement fitted into Randomized Complete Block Design in three replicates. Data were collected on agronomic traits of castor. Organic fertilizer significantly (P < 0.05) expedited days to flowering and increased height to primary raceme in 2021. SD had significant (P < 0.05) effect on days of flowering, seed yield, and yield attributes of castor. Castor sown at SD1 and SD2 in 2022 produced high seed yield of 773.7 and 799.1 kg/ha higher by 498.8% and 503.0% than SD8 yield of 129.2 kg/ha. It is concluded that for optimum castor seed production, sowing should be done from June 18 to latest July 2 with or without organic fertilizer in the humid tropics
Castor wilt
No full textThe technical bulletin on "castor wilt" contains information on distribution, economic importance, symptoms, variability of pathogen, nematode –fungus interaction, disease cycle, screening of castor germ plasm for identification of resistant sources and management of wilt disease.Not AvailableDirectorate of Oilseeds Research, Hyderaba
Pure polyurethane and castor oil based polyyurethane synthesis and characterization
No full textIn this study, the physico-chemical properties of high performance polyurethane synthesized from poly propylene glycol (PPG) in comparison with a combination of PPG and castor oil, is studied using the in-situ polymerization technique. The variations in properties of both types of polyurethanes are evaluated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and the thermogravimetric analysis (TGA) technique. Tensile strength properties were investigated by film tensile testing equipment. The results indicated the presence of large -CH stretching in the castor oil mixed polyurethane with a larger oxidative thermal stability over pure PPG polyurethanes. The tensile properties were found to be almost comparable in pure and mixed polymers, signifying the usage of mixed polymers in the future to overcome the environmental and economic crisis in polyurethane synthesis
Not Available
No full textNot AvailableCastor (Ricinus communis L.) belonging to Euphorbiaceae family is an important non-edible industrial oilseed crop. The Castor Germplasm Management Unit at ICAR-IIOR, Hyderabad is currently maintaining 3289 accessions.The entire collection of 3289 accessions has been characterized using 23 morphological descriptors developed at ICAR-IIOR, and the same accessions have been characterized for 19 quantitative traits. Several trait-specific accessions possessing resistance to biotic and abiotic resistance were identified based on screening in artificial stress conditions. In addition accessions possessing extra=early maturity, high ricinoleic acid, high seed weight, high seed yield and long longevity were identified. Fifteen accessions have been registered with PGRC, ICAR. The promising accessions were well utilized in AICRP (Castor) breeding programmesNot Availabl
Screening method for gray mold of castor
No full textInstitute projectBotryotinia ricini (Godfrey) Whetzel, the gray mold pathogen of castor, inflicts serious crop losses in short periods. The present study was aimed at to develop a season-independent screening technique for gray mold in castor. Conidia from in vitro-raised pure culture of the anamorph Amphobotrys ricini were sprayed on separated mature as well as immature capsules of 4 castor genotypes (DCS 9, RG 2787, RG 3309 and RG 3216 R), placed in glass petriplates and incubated at 22–24ºC for 7 days. Genotype DCS-9 was highly susceptible to the disease, while genotype RG 3216 R exhibited least susceptibility. Immature capsules were more susceptible to disease than mature capsules. RNA degradation occurred in treated samples 2 days after treatment and control gene (UBQ) expression was unaffected till 4 hr post-inoculation. Thus a reproducible, lab-based, season-independent, screening technique using petri-plates and severed castor capsules was developed for differential gene expression analysis of candidate genes involved in early infection and elucidating host-pathogen interactions in castor gray mold.ICAR- IIO
Deep anisotropic dry etching of silicon microstructures by high-density plasmas
No full textThis thesis deals with the dry etching of deep anisotropic microstructures in monocrystalline silicon by high-density plasmas. High aspect ratio trenches are necessary in the fabrication of sensitive inertial devices such as accellerometers and gyroscopes. The etching of silicon in fluorine-based plasmas is isotropic. To obtain anisotropy the addition of sidewall passivation is necessary. This is achieved with both oxygen passivation at low temperatures and fluorocarbon passivation at room temperature. A quantitative approach was pursued to explain the etching mechanism. The etch results were analysed using the measured plasma species fluxes and the surface composition. Moreover, the transport of the plasma species in narrow anisotropic structures is a fundamental factor determining the etch rate and the profile evolution. The experimental methods such as the etching equipment, plasma diagnostics, surface analysis and sample preparation are described in chapter 2. Three etching processes were investigated: the cryogenic etching process with oxygen passivation at low temperatures, the Bosch process with fluorocarbon passivation at room temperature and the novel triple pulse process that was developed in our laboratory. The polymer deposition mechanism and the characteristic role of the ions are also explained. The cryogenic etching process is discussed in chapter 3. Fluorine radicals, oxygen radicals and ion bombardment are responsible for the three main sub-processes, that is, etching, sidewall passivation and depassivation of the trench bottom, respectively. Etching experiments with an extremely low ion-to-radical flux ratio were used to reveal the etching mechanism. Crystal orientation dependent etching leading to Si(111) crystal facets is observed in a surface kinetics controlled regime. By varying the plasma conditions it is possible to adjust the etching mechanism from fluorine-limited to ion-limited. Controlled etching is obtained because the etching is tuned from aspect ratio dependent in the fluorine-limited domain to aspect ratio independent in the ion-limited domain. The transport of radicals in high aspect ratio trenches is an important limiting factor and was investigated with special structures. The etch results are described by an analytic model that is based on the surface site balance of fluorine and oxygen radicals. The results are further explained with a Monte Carlo simulation model. The Bosch process is clarified in chapter 4. The anisotropy of the etched structures is controlled by balancing the etching and passivation pulse. However, the maximal obtainable aspect ratio is limited by convergence of the trench sidewalls due to excessive passivation. The maximal obtainable aspect ratio increases if the ion-to-radical flux ratio increases. The transport of ions is an important limiting factor in the depassivation of the bottom of the trench. Divergence of the ion beam leads to a reduction of the ion flux, so that the fluorocarbon passivation is insufficiently removed near the base of the sidewalls. The average ion angle was measured and correlated to the maximal obtainable aspect ratio. The Bosch process was improved at the depassivation side with the triple pulse process and at the passivation side with preferential sidewall deposition. The triple pulse process that is described in chapter 5 has the aim to improve the depassivation in deep trenches. The three main sub-processes are decoupled using a separate depassivation pulse directly after the etching and passivation pulses. The fluorocarbon passivation is efficiently removed with low-pressure, high-density, oxygen-based plasmas. The investigated plasma chemistries include O2, CO2 and SO2. The triple pulse process leads to better profile control with a straight trench bottom. However, the maximal obtainable aspect ratio is comparable to the Bosch process because a larger etch depth and a small lateral etch cancel out. The polymer deposition mechanism is treated in chapter 6 with the aim to understand the fluorocarbon passivation in deep trenches. The deposition on plane surfaces and on special structures was investigated to distinguish between the radical-induced and ion-enhanced components. A simple analytical model, which explains the main deposition characteristics, was developed. Preferential sidewall deposition is obtained for higher ion fluxes and higher bias voltages where sputtering plays an important role. In this case no fluorocarbon passivation has to be removed from the bottom of the trench. The trench profile was optimised in the Bosch process by tuning the bias voltage during etching and passivation independently. It resulted in perfectly anisotropic trenches but the maximal obtainable aspect ratio was still limited by a small lateral etch. The characteristic role of the ions in the etching mechanism is explained in chapter 7. Ion-induced etching of both SiC in a SF6-O2 plasma and Si in a Cl2 plasma were investigated. The impact of the ions on the profile evolution can be examined more explicitly because spontaneous chemical reactions are absent for these plasma-material systems. The etching mechanism varies from fluorine-limited to ion-limited depending on the radical-to-ion flux ratio. Microtrenches are observed for an ion-limited etching mechanism. Fluorine-limited SiC etching is aspect ratio dependent in contrast to ion-limited SiC etching, which is aspect ratio independent. The etching of high aspect ratio SiC structures is limited by the positive sidewall taper. This is presumably caused by insufficient removal of the thin fluorocarbon layer on the surface. Si etching in a Cl2 plasma is always aspect ratio independent in contrast to SiC etching because of the low reaction probability. The conclusions and recommendations of this thesis are given in chapter 8.Applied Science
PURE POLYURETHANE AND CASTOR OIL BASED POLYURETHANE: SYNTHESIS AND CHARACTERIZATION
No full textIn this study, the physico-chemical properties of high performance polyurethane synthesized from poly propylene glycol (PPG) in comparison with a combination of PPG and castor oil, is studied using the in-situ polymerization technique. The variations in properties of both types of polyurethanes are evaluated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and the thermogravimetric analysis (TGA) technique. Tensile strength properties were investigated by film tensile testing equipment. The results indicated the presence of large -CH stretching in the castor oil mixed polyurethane with a larger oxidative thermal stability over pure PPG polyurethanes. The tensile properties were found to be almost comparable in pure and mixed polymers, signifying the usage of mixed polymers in the future to overcome the environmental and economic crisis in polyurethane synthesis
Ricin trafficking in plant and mammalian cells
No full textRicin is a heterodimeric plant protein that is potently toxic to mammalian and many other eukaryotic cells. It is synthesized and stored in the endosperm cells of maturing Ricinus communis seeds (castor beans). The ricin family has two major members, both, lectins, collectively known as Ricinus communis agglutinin ll (ricin) and Ricinus communis agglutinin l (RCA). These proteins are stored in vacuoles within the endosperm cells of mature Ricinus seeds and they are rapidly broken down by hydrolysis during the early stages of post-germinative growth. Both ricin and RCA traffic within the plant cell from their site of synthesis to the storage vacuoles, and when they intoxicate mammalian cells they traffic from outside the cell to their site of action. In this review we will consider both of these trafficking routes
The emulsifying Properties of Terminalia randii baker F. Gum in castor oil and liquid paraffin emulsions
No full textBackground: Emulsifying agents are added to preparations to facilitate the process of emulsification during manufacture and also to assure the stability of emulsion during the shelf life of the product. Natural gums have been used as emulsifying agents because they are readily available, non-toxic and cheap.Objectives: In this study, the emulsifying properties of Terminalia randii gum were assessed and compared with a standard emulsifier (Tragacanth gum) using castor oil and liquid paraffin .Method: Different concentrations (1-10% w/v) of the mucilages of Terminalia randii gum and Tragacanth were prepared. Using wet gum method, castor oil (fixed oil) was mixed with the mucilage and methyl paraben was added. Distilled water was used to make up to volume. The procedure was repeated for liquid paraffin (mineral oil). The emulsions were assessed using creaming rate, globule size and viscosity.Results: Castor oil and liquid paraffin emulsions containing Terminalia gum did not show any form of creaming at high concentration (10% w/v). At low concentration (1-2% w/v), the emulsions cracked within 24 hours of preparation. There was no significance (p>0.05) difference in the globule sizes of emulsions containing Terminalia or tragacanth gum. The viscosity of emulsions containing Terminalia gum increased with increase in concentration of emulsifier and time. It was observed that after one week (168 hours) the viscosity of emulsions containing tragacanth started decreasing and this coincided with the time the emulsions started to cream or eventually cracked.Conclusion: Terminalia randii gum produced more stable emulsions and thus could be used as alternative emulsifying agent.Keywords: Terminalia randii gum, Emulsifying agent, Castor oil, Liquid Paraffin, Emulsion
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