Time filter

Source Type

Jha S.K.,Indian Central Soil Salinity Research Institute | Nayak A.K.,Indian Central Rice Research Institute | Sharma Y.K.,University of Lucknow
Ecotoxicology and Environmental Safety | Year: 2011

A study was carried out to assess toxicological risk from the fluoride (F) exposure due to ingestion of vegetables and cereal crops such as rice and wheat grown in potentially fluoridated area (brick kiln and sodic areas), of different age groups in Unnao district, Uttar Pradesh, India. Fluoride contents in vegetables and cereal were found to be in the order brick kiln sites>sodic sites>normal sites. Among vegetables maximum F concentration was found in spinach and mint, whereas in cereal crops, wheat accumulated more F than rice. The exposure dose of F was determined using estimated daily intake (EDI) and bio-concentration factor (BCF) of F. The children of age group 3-14 years in the potentially fluoridated area were found to be at the risk of fluorosis. The mean BCF value of F was the highest in mint (36.6mg/kgdwtplant/mg/kgdwtsoil), followed by spinach (33.99mg/kgdwtplant.mg/kgdwtsoil). © 2011 Elsevier Inc. Source

Parida S.K.,Indian Agricultural Research Institute | Mukerji M.,Institute of Genomics and Integrative Biology | Singh A.K.,Indian Agricultural Research Institute | Singh N.K.,Indian Agricultural Research Institute | And 2 more authors.
BMC Genomics | Year: 2012

Background: Single nucleotide polymorphism (SNP) validation and large-scale genotyping are required to maximize the use of DNA sequence variation and determine the functional relevance of candidate genes for complex stress tolerance traits through genetic association in rice. We used the bead array platform-based Illumina GoldenGate assay to validate and genotype SNPs in a select set of stress-responsive genes to understand their functional relevance and study the population structure in rice.Results: Of the 384 putative SNPs assayed, we successfully validated and genotyped 362 (94.3%). Of these 325 (84.6%) showed polymorphism among the 91 rice genotypes examined. Physical distribution, degree of allele sharing, admixtures and introgression, and amino acid replacement of SNPs in 263 abiotic and 62 biotic stress-responsive genes provided clues for identification and targeted mapping of trait-associated genomic regions. We assessed the functional and adaptive significance of validated SNPs in a set of contrasting drought tolerant upland and sensitive lowland rice genotypes by correlating their allelic variation with amino acid sequence alterations in catalytic domains and three-dimensional secondary protein structure encoded by stress-responsive genes. We found a strong genetic association among SNPs in the nine stress-responsive genes with upland and lowland ecological adaptation. Higher nucleotide diversity was observed in indica accessions compared with other rice sub-populations based on different population genetic parameters. The inferred ancestry of 16% among rice genotypes was derived from admixed populations with the maximum between upland aus and wild Oryza species.Conclusions: SNPs validated in biotic and abiotic stress-responsive rice genes can be used in association analyses to identify candidate genes and develop functional markers for stress tolerance in rice. © 2012 Parida et al.; licensee BioMed Central Ltd. Source

Datta A.,University of Aberdeen | Datta A.,Indian Central Rice Research Institute | Santra S.C.,Kalyani University | Adhya T.K.,Indian Central Rice Research Institute
Atmospheric Environment | Year: 2013

In the tropical experimental rice field of Central Rice Research Institute, Odisha, India, an experiment was conducted during the dry season (January-April) and wet season (July-November) of rice cultivation to study the effect of nitrogen (N), phosphorus (P) and potassium (K) fertilizer application on grain yield and methane (CH4) emission. The experiment was carried out with five treatments (No fertilizer (control), N-fertilizer, P-fertilizer, K-fertilizer and N + P + K fertilizer) with three replicates of each under a completely randomized block design. Significantly higher CH4 emission was recorded from all plots during wet season. Among fertilizer applied plots, significantly higher CH4 emission was recorded from N-fertilizer applied plots (dry season: 80.27 kg ha-1; wet season: 451.27 kg ha-1), while significantly lower CH4 emission was recorded from N + P + K applied plots (dry season: 34.60 kg ha-1; wet season: 233.66 kg ha-1). Low cumulative CH4 emission to grain yield ratio was recorded from N + P + K applied plots during both seasons (83.57 kg Mg-1 grain yield during dry season and 77.14 kg Mg-1 grain yield during wet season). CH4 emission from different treatment was positively correlated with microbial biomass carbon (r = 0.516), readily mineralizable carbon (r = 0.621) and sugar (r = 0.340) content of the soil. Negative CH4 emission was recorded during the fallow period which may be attributed to higher methanotrophic bacterial population. Study suggests that the effects of P and K-fertilizer on CH4 emission from rice field along with the CH4 emission during the fallow period need to be considered to reduce the uncertainty in upscaling process. © 2012 Elsevier Ltd. Source

Das S.,Indian Central Rice Research Institute | Adhya T.K.,Indian Central Rice Research Institute
Geoderma | Year: 2014

Methane and nitrous oxide emissions, their global warming potential, carbon efficiency ratio and related biogeochemical properties of a tropical soil planted to rice were investigated under different N management [i.e. urea-N (120kgN ha-1), rice straw (RS) (30kgN ha-1)+urea-N (90kgN ha-1), compost (C) (30kgN ha-1)+urea-N (90kgN ha-1) and poultry manure (PM) (30kgN ha-1)+urea-N (90kgN ha-1)]. CH4 fluxes were increased by 82.7%, 65.1%, 63.4% and 31.9% in RS+urea-N, C+urea-N, PM+urea-N and urea-N, respectively whereas percentage increase in cumulative N2O emission was 390.6, 371.8, 315.6, and 253.1 in PM+urea-N, urea-N, C+urea-N and RS+urea-N, respectively over control (no fertilizer amendment). However, increase of GWPs in different manure+urea-N over that of control were 85.5%, 69.2%, 68.8% and 37.6% in RS+urea-N, C+urea-N, PM+urea-N and urea-N, respectively. Microbial biomass carbon (MBC), readily mineralizable carbon (RMC) and fluorescence diacetate (FDA) hydrolysis activity were significantly affected by integrated N-management and followed the order of C+urea-N>PM+urea-N>RS+urea-N>urea-N>control. With considerably high microbial biomass C and microbial activity, high C efficiency ratio, high yield and low greenhouse gas intensity, C+urea-N could be a better option to mitigate CH4 and N2O emissions and to maintain soil biological quality and yield in tropical paddy. © 2013 Elsevier B.V. Source

Das S.,Indian Central Rice Research Institute | Adhya T.K.,Indian Central Rice Research Institute
Soil Biology and Biochemistry | Year: 2012

Response of methanogenesis and methanotrophy to elevated carbon dioxide (CO 2) could be affected by changes in soil moisture content and temperature. In soil microcosms contained in glass bottles and incubated under laboratory conditions, we assessed the impact of elevated CO 2 and temperature interactions on methanogenesis and methanotrophy in alluvial and laterite paddy soils of tropical origin. Soil samples were incubated at ambient (370μmolmol -1) and elevated (600μmolmol -1) CO 2 concentrations at 25, 35 and 45°C under non-flooded and flooded conditions for 60d. Under flooded condition, elevated CO 2 significantly increased methane (CH 4) production while under non-flooded condition, only marginal increase in CH 4 production was observed in both the soils studied and the increase was significantly enhanced by further rise in temperature. Increased methanogenesis as a result of elevated CO 2 and temperature interaction was mostly attributed to decreased soil redox potential, increased readily mineralizable carbon, and also noticeable stimulation of methanogenic bacterial population. In contrast to CH 4 production, CH 4 oxidation was consistently low under elevated CO 2 concentration and the decrease was significant with rise in temperature. The low affinity and high affinity CH 4 oxidation were faster under non-flooded condition as compared to flooded condition. Admittedly, decreased low and high affinity CH 4 oxidation as a result of elevated CO 2 and temperature interaction was related to unfavorable lower redox status of soil and the inhibition of CH 4-oxidizing bacterial population. © 2011 Elsevier Ltd. Source

Discover hidden collaborations