Strategies for climate change impacts on irrigated crops in National Capital Region of India

Irrigation has helped in increasing food production and achieving food security in India. However, climate change is expected to affect the crop production in irrigated area particularly in groundwater irrigated areas. This study was undertaken for suggesting strategies to climate change impact on irrigated crops based on projected change in crop water requirement and groundwater availability for irrigation in the National Capital Territory of Delhi. Prevailing groundwater recharge in the study area during monsoon was 4.01 MCM (Million cubic meter). The same for various scenarios varied from -15.47 MCM to 5.08 MCM. It was revealed that groundwater recharge would increase if it is estimated based on the climate prediction done using local weather data. The impact of climate change on groundwater availability is evident in scenarios based on INCCA and IPCC predictions where it varied from -2.66 MCM to 1.02 MCM. Contrary to common perceptions, crop water requirement of prevailing cropping system would not increase in future if all the important climatic parameters are considered for its prediction. This may be due to the fact that effect of increase in temperature on crop water requirement may be compensated by decrease in other climatic parameters such wind speed and duration of daily sunshine hours. Results indicated that climate change may not have much impact on sustainability of prevailing cropping system as per the crop water requirement is concerned. Based on water requirement and groundwater availability under various climate change scenarios, appropriate strategies to cope up the climate change impact on irrigated crops have been suggested

Environmental Control Measures in Sponge Iron Industry with Particualr Reference to Tata Sponge Iron Limited

Direct reduced iron or sponge iron technology was developed as an alternate route for steel making and is considered as a clean technology. The waste generation and gas emissi-ons from this route of steel making are far less when comp-ared to the conventional blast furnace route. The paper details the efforts of Tata Sponge Iron Limited to make the process a clean technology without affecting its surroundings and natural resources

Ferns: heavy metal guzzlers can replace expensive methods of controlling pollution

Now Indian ecotype of brake fern found in Kerala has been found to exhibit similar properties. A team of researchers from National Environmental Engineering Institute (NEERI) found that the fern could also help remove chromium from the soil and water. The study published in March 25 issue of Current Science says this particular ecotype of brake fern is found only in India. For most of the developing countries, including India, brake fern plantation could help in reducing the expenditure required on mitigating heavy metal pollution using modern technologies

Efficacy of Three Different Plant Species for Arsenic Phytoextraction from Hydroponic System

Arsenic (As) is one of the heavy metals which causes acute bio-toxicity even at low concentration and has disastrous effect on environment. In some countries, As contamination has become alarming and increasing day by day as consequences of unsustainable management practices. Many existing physical, chemical and biological processes for As removal from water system are not feasible due to techno-economic limitations. The present study highlights the scope of biological strategy for As removal through phytoextraction. Arsenic uptake and accumulation in the biomass of three plant species and their As tolerance abilities have been investigated to develop an efficient phytoextraction system in combination of these plant species. Three non-crop plant species, Pteris vittata; Mimosa pudica, and Eichhornia crassipus were treated with 0–200 mg/L As in liquid nutrient solution for 14 days. P. vittata accumulated total 9,082.2 mg (8,223 mg in fronds) As/kg biomass and Eichhornia total 6,969 mg (4,517 mg in fronds)/kg biomass at 200 mg/L As concentration, respectively. Bioaccumulation factor (BF) and translocation factor (TF) were estimated to differentiate between excluders, accumula¬tors and accumulation in above ground biomass. Pteris and Eichhornia have highest BF (67 and 17) and TF (64 and 3), respectively. In contrast, Mimosa accumulated up to 174 mg As/kg plant biomass which is low in comparison with other two plants, and both BF and TF were ≤1. This study reveals that Pteris and Eichhornia are As hyperaccumulator, and potential candidates for As removal from water system

Character Association and Path Analysis for Yield, Iron Content and Component Traits in Indigenous Rice Germplasm

Not AvailableRice is one of the major staple foods which contribute the energy source of nutrition. As variation in micronutrients is a major problem affecting the health of people, so selection for indigenous rice germplasm with higher micronutrient for iron and zinc is need of the hour. For selection of characters, character association and direct and indirect contribution of characters play an important role. The present investigation was conducted taking 94 germplasms using augmented design. Observations were recorded on 12 quantitative and 3 quality characters from five randomly selected plants in each genotype. The characters like days to 50 % flowering, days to maturity, plant height (cm), number of tiller per plant, panicle length (cm), number of grains per panicle, 1000-grain weight (g) yield per plant (g), harvest index (%), grain length (mm) grain width (mm), grain L/B ratio, amylose content, gelatinization temperature and iron content in brown rice (ppm) were taken and analyzed for character association and path analysis studies. The characters like 1000-grain weight, harvest index, grain length and grain breadth shown significant association with yield while there was negative association of harvest index with iron content of brown rice. Direct and indirect contributions also supported the character association in same manner. So, selection of 1000-grain weight, grain length and grain breadth are important characters to select plants for improvement of iron content in brown rice as well as yield.Not Availabl

Arsenic hyperaccumulation efficiency depends on time and tissue in Pteris vittata

The metalloid arsenic is a toxic environmental pollutant. Arsenic pollution becomes serious due to mining, mineral, smelting and tannery industry. Leaching of naturally occurring arsenic into drinking water aquifers, has been reported in many countries including India and Bangladesh. Available engineering methods for remediation is costly and difficult. Many plant species reported to accumulate arsenic. Pteris vittata has been reported as arsenic hyperaccumulator. An Indian eco-type of P. vittata has been used to study the arsenic accumulation. The plants were grown in arsenic containing soil along with soil without arsenic (control). The ferns were separated into two portions, i.e., above ground (fronds), stage specific as well as tissues from different position of pinnae and below ground (roots and rhizomes). Futher, it was also harvested at different time interval. Dried fern samples (0.1 g) were digested with mixture of concentrated nitric acid and perchloric acid. Heavy metal measurement in foliar and root samples was performed with ICP-OES. Tissue specific arsenic accumulation indicates that juvenile leaf contains highest arsenic than mature leaf. Middle pinnae of mature leaf show high arsenic content compared to upper and lower pinnae. Among the underground parts of the plant, rhizome contains high arsenic than roots. Further, time dependent arsenic accumulation study indicates that active accumulation of arsenic starts from day 7 to day 30 in leaf tissue, while in roots, day 3 to 7 show sudden increase and no much drastic change in accumulation from day 7 onwards

cDNA cloning and characterization of tryptophan synthase alpha subunit from Polygonum tinctorium

Polygonum tinctorium is a cultivated plant that produces indigo, a natural blue dye. Its leaves contain a large amount of indican (indoxyl-beta-D-glucoside), a colorless precursor of indigo. The enzyme beta-glucosidase, which degrades indican, is present in leaf cells. If the leaves ar e scratched because of some external factors, indican is enzymatically degraded into indoxyl and glucose. Because of the chemical instability of indoxyl, it is immediately oxidized to indigo by atmospheric oxygen. Beta-glucosidase is located in chloroplasts, whereas the substrate indican is stored in vacuoles. Therefore, indigo is only produced if leaf cells are physically broken. The insoluble indigo may have a negative effect on infectious fungi and bacteria as well as on invasive insects and other animals. We hypothesize that the physiological role of indican as a secondary metabolite is of a defense system against predators. In a previous study, we have shown that indican is synthesized from indoxyl and UDP-glucose by the catalysis of UDP-glucosyltransferase. The substrate indoxyl is probably produced by the hydroxylation of indole catalyzed by cytochrome P450. Indole is an intermediate product in tryptophan syn thesis, which is the final step of the shikimic acid pathway, a primary metabolic pathway. The tryptophan synthase consists of four subunits: two alpha subunits (TSA) and two beta subunits (TSB). Only TSA catalyzes the synthetic reaction of indole. Subsequently, indole is converted to tryptophan by the action of TSB. The purpose of this study is to uncover the complete indican synthetic pathway and to provide insight into the switching mechanism from primary to secondary metabolism. Here, we report on the cDNA cloning, expression, and characterization of TSA from P. tinctorium. Transcriptome analysis using mRNA from P. tinctorium leaf tissue resulted in a one-fragment sequence that has homology with sequences from other plant TSAs. Based on this sequence, the RACE method was used to get the complete length of the TSA cDNA. The obtained cDNA consisted of 1,469 bp encoding a polypeptide of 315 amino acids. The primary structure contained the consensus sequences of TSAs and the regions for interaction with beta subunits. P. tinctorium TSA, which we named as ptTSA1, showed high homology to some enzymes from plants; this was the case particularly with TSA from Isatis tinctoria, another indigo plant, which showed 95.7% homology to ptTSA1. To analyze the properties and functions of ptTSA1, the recombinant protein was expressed in Escherichia coli. In addition, the ptTSA1 cDNA was used to examine whether ptTSA1 could complement a TSA deletion in E. coli. ptTSA1 protein expression and mRNA levels in various tissues of P. tinctorium were examined by the Western blot analysis and semi-quantitative RT-PCR. These expression patterns were also compared with those of TSBs. Here, we will further discuss regarding the analysis of ptTSA1 and the interaction between TSA and TSB

Analysis of Stability and G × E Interaction of Rice Genotypes across Saline and Alkaline Environments in India

Genotype × environment (G × E) interaction effects are of special interest for identifying the most suitable genotypes with respect to target environments, representative locations and other specific stresses. Twenty-two advanced breeding lines contributed by the national partners of the Salinity Tolerance Breeding Network (STBN) along with four checks were evaluated across 12 different salt affected sites comprising five coastal saline and seven alkaline environments in India. The study was conducted to assess the G × E interaction and stability of advanced breeding lines for yield and yield components using additive main effects and multiplicative interaction (AMMI) model. In the AMMI1 biplot, there were two mega-environments (ME) includes ME-A as CARI, KARAIKAL, TRICHY and NDUAT with winning genotype CSR 2K 262; and ME-B as KARSO, LUCKN, KARSA, GOA, CRRI, DRR, BIHAR and PANVE with winning genotypes CSR 36. Genotypes CSR 2K 262, CSR 27, NDRK 11-4, NDRK 11-3, NDRK 11-2, CSR 2K 255 and PNL 1-1-1-6-7-1 were identified as specifically adapted to favorable locations. The stability and adaptability of AMMI indicated that the best yielding genotypes were CSR 2K 262 for both coastal saline and alkaline environments and CSR 36 for alkaline environment. CARI and PANVEL were found as the most discernible environments for genotypic performance because of the greatest GE interaction. The genotype CSR 36 is specifically adapted to coastal saline environments GOA, KARSO, DRR, CRRI and BIHAR and while genotype CSR 2K 262 adapted to alkaline environments LUCKN, NDUAT, TRICH and KARAI. Use of most adapted lines could be used directly as varieties. Using them as donors for wide or specific adaptability with selection in the target environment offers the best opportunity for widening the genetic base of coastal salinity and alkalinity stress tolerance and development of adapted genotypes. Highly stable genotypes can improve the rice productivity in salt-affected areas and ensure livelihood of the resource poor farming communities

Non-resonant microwave absorption studies of superconducting MgB_2

Non-resonant microwave absorption(NRMA) studies of superconducting MgB_2 at a frequency of 9.43 GHz in the field range -50 Gauss to 5000 Gauss are reported. The NRMA results indicate near absence of intergranular weak links. A linear temperature dependence of the lower critical field H_c1 is observed indicating a non s-wave superconductivity. However, the phase reversal of the NRMA signal which could suggest d-wave symmetry is also not observed.Comment: 8 pages, 2 figure

Cell cultures and molecular investigation on Polygonum tinctorium and Indigofera tinctoria plants to understand indican biosynthesis

Indican biosynthesis in Indigofera tinctoria and Polygonum tinctorium plants is of topical interest due to its academic and industrial relevance for indigo dye production. Dye yield depends on indican content in the plant biomass. Cell culture and molecular biological investigations were carried out to assess indican biosynthesis in these plants. Tissue culture protocols were optimized for explant identification, decontamination, in vitro culture medium & suitable growth regulators and culture conditions for P. tinctorium at Okayama University of Science, and I. tinctoria at CSIR-NEERI. Four different growth hormones i.e. BA, Kin, NAA, 2,4-D, at 0.01 –2 mg L-1 culture medium, in random combination, and two different explants i.e. leaf and internode of both plants were experimented. In both plants, callus proliferation was better from leaf tissue with growth index (GI) up to 10 on MS agar gelled medium fortified with BA+NAA in comparison to BA+2,4-D. Suspension cell cultures of I. tinctorium were induced in MS liquid medium with only 2,4-D through 3 stages with GI up to 30. In vitro raised cell biomass of I. tinctorium presented higher indican synthesis (p> 0.5) in comparison to that of P. tinctorium. Both of these plants synthesize indican, but the differential response under in vitro is interesting. Total transcriptomes of both plants were worked out and annotated. Comparative analysis of transcriptome profile indicated >80% genes are similar for the indican biosynthetic pathways. Complete alignment of both transcriptomes and validation for biosynthesis pathways specific genes is needed in both the plants to ascertain their differential expression