Authors:M. Banerjee, P. Chandra, D. Shanker, H. Singh, and V. Singh
Movement and abstraction of groundwater in the geological formations are dependent on the hydro-geological parameters of the aquifers. The purpose of any aquifer test is to determine the hydro-geological parameters. Among the basic parameters are the specific storage, permeability and leakage coefficients. The hydro-geological parameters are hidden in the field test data and their identification is possible using the available physically plausible models suitable for the prevailing field circumstances. In this context, a generalized theoretical solution for the effect of partial penetration superimposed over the full penetration on draw-down in a large-diameter well in artesian aquifer discharging at a constant rate has been presented for non-dimensional quantities describing the variable geometries of wells. The well-function curves are developed by varying the percentage amount of drilling and the percentage amount of casing lowered which then control to vary the percentage amount of open-hole or screened interval for the three categories: when the diameter of the cased interval in which the water level changes is greater than, equal to, and less than the diameter of the open interval. The skin effect and the effect of leakage are neglected. A comparison of results with the published works has also been presented. The present study is useful in such areas where wells are located either in harder or in collapsible loose formations; and a decision is required that, at the planning, construction, or development stage, as to what extent the amount of drilling be reduced, and/or an additional amount of casing be lowered within the aquifer. Also this reduces the cost of well construction and development in a specific situation.
Authors:D. R. Batish, H. P. Singh, and R. K. Kohli
A study conducted to determine the ecological status of vegetation under a Casuarina equisetifolia L. plantation revealed that the number of species types, density and biomass of the understorey were drastically reduced compared to an adjoining grassland area. In general, vegetation under Casuarina was characterised by the presence of a few dominants with a trend towards homogeneity. On the other hand, the vegetation in the grassland was heterogeneous, with conspicuous spatial pattern and, thus, more stable. Indices of richness (indicating numerical strength), evenness (representing spatial distribution), and diversity (combining both richness and evenness) also indicated a marked difference in the vegetation between the two sites. The Shannon index, indices of richness and evenness, and Hill. s diversity measures were greater in grassland areas than in Casuarina plantation, thereby signifying a richer, more diverse and even vegetation in the grassland. In contrast, the Simpson index of dominance which shows an inverse relation with diversity, was greater under the Casuarina plantation. The reasons for the restrained vegetation under Casuarina were explored in terms of allelopathic interference of various tree parts (fresh as well as fallen) as one of the major factor. The leaf leachates collected under the canopy of Casuarina trees in the plantation were found to have deleterious effect on the growth of Medicago sativa and Ageratum conyzoides and were rich in phenolics. The extracts prepared from different tree parts such as needles, female cones and litter adversely affected the growth and dry weight accumulation in M. sativa and A. conyzoides. An appreciable amount of water-soluble phenolics, known phytotoxins, was estimated in the fog leachates and different plant parts under use. It is concluded that phenolics released from the green needles and litter of the tree adversely affect the understorey vegetation.
Authors:H. Sharma, R. Behl, K. Singh, N. Narula, and P. Jain
Field experiments were conducted over two years under low input conditions to know the influence of bio-inoculants, namely arbuscular mycorrhiza fungi (AMF,
Azotobacter chroococcum (Azc)
on the performance and gene effects for important root and plant characters in three crosses of wheat (WH147×WH157, WH147×PBW175 and WH147×WH542). Six generations representing P
populations of each cross were grown in randomized block design with three replications. The estimate of means (m) indicated that bio-inoculants enhanced the mean performance of most of the characters and root length density and grain yield in some crosses only. Crop season also showed considerable effect on impact of bio-inoculants. The joint scaling test revealed adequacy of additive-dominance model of gene effects for root biomass, root length density, flag leaf area, tillers/plant, grain weight and grain yield in all the crosses and bio-inoculants treatments in both years. The AMF treatment brought about changes in the magnitude and significance of additive component for root biomass, plant height, flag leaf area in all the three crosses. Both additive (d) and dominance (h) components were affected with respect to grain yield in WH147×WH157 and WH147×WH542. The dominant component was important for tillers/plant, grain yield, root length in control, as well as bio-inoculants treated populations of WH147×PBW175 but treatment of AMF and AMF+
reduced the magnitude of h and increased the magnitude of d. Digenic interactions were prominent for grains/spike in WH147×WH157. Magnitude of digenic interactions was higher under bio-inoculation. Simple pedigree and bulk pedigree methods are suggested to capitalize on adequate additive gene effects for developing bio-inoculants responsive wheat genotypes.
Authors:N. H. Singh, J. Mathai, V. N. Neelakandan, D. Shankar, and V. P. Singh
A series of unusual geological incidents have occurred throughout the Kerala State (southwest Peninsular India) during the year 2001 mainly in two active phases i.e. February to March, and June to November 2001. In the beginning during February-March 2001, oscillations and rise in water levels, wavy formations and spouting up of water in the open wells, cracks in the buildings, perceptible ground fissures, shaking of trees/bushes and enhanced microearthquake activity have occurred. Collapse of shallow open wells, draining of water, lowering of water level, land subsidence, ground fissures etc., and further increased microearthquake activity were the dominant incidents in various parts of the State during June to November 2001. Interestingly, no such incidents had occurred in the past in this region. The frequency of all the above incidents, including microearthquakes activity, reduced drastically to background level beyond November 2001 except a few earthquakes during 2002 and 2003. The incidents are distributed in a vast area irrespective of geology and topography right from coastal stretch to hinterlands in the Western Ghats of India. This chain of incidents was preceded by two moderate size earthquakes of M ~ 5 on 12 December 2000 and 7 January 2001 which were not capable to trigger such widespread incidents in the region. The temporal patterns of these incidents clearly indicate the phenomenon of rapid ground vibrations at several occasions possibly due to movement of crustal block along certain active fault. This geological process perhaps lead to uplift and tilt of the ground giving rise to several underground water related anomalies and incidents of land deformations. The temporal patterns of individual incident also did not show any clear inter-relationships indicating that all these incidents were caused by a single internal geological process possibly due to converging trend of tectonic stress through the process of redistribution. It is inferred that these incidents constitute a well defined patterns of precursory sequence to a future large seismic activity in the southwest part of Peninsular India. The existence of the present chain of events can be explained by dilatancy diffusion model. Using the spatial distribution of these incidents including microearthquake activity and past significant earthquakes, an east-west trending potential area (10.7-10.9°N; 76.0-76.8°E) is delineated in the central Kerala region as the preparatory zone for the location of future earthquake.
Authors:P. Sharma, H.K. Chaudhary, N.V. Manoj, K. Singh, A. Relan, and V.K. Sood
The present research endeavor was undertaken to depict the response of different generations viz., F1, F2, BC1F1, BC1F2, BC1F3, BC1F4 and BC1F5 of triticale × wheat and wheat × rye hybrids towards the different parameters of haploid induction. The experimental material included the different generations obtained utilizing five genotypes of triticale (DT-123, DT-126, TL-2900, TL-2908 and TL-9335), four genotypes of Himalayan rye (Karoki rye, shanoor rye, tino rye and triloki rye) with various elite bread wheat genotypes as parents in wide hybridization programme. The triticale × wheat and wheat × rye recombinants were further subjected to Imperata cylindrica-mediated chromosome elimination approach of doubled haploidy breeding. The variability in the haploid induction parameters was observed to be under genetic control for embryo formation and regeneration, while pseudoseed formation was only affected by auxin treatment. Among the different generations, the backcross generations viz., BC1F1 and BC1F2 were found to exhibit significant positive response towards haploid induction parameters in both triticale × wheat and wheat × rye hybridization. Knowledge of effective generation for haploid induction in triticale × wheat and wheat × rye hybridization not only saved the time and energy but also enhanced the efficiency of haploid induction.
Authors:R.K. Sharma, M. Osmanzai, R.P. Singh, H.J. Braun, and R.C. Sharma
High yielding, stable wheat (Triticum aestivum L.) cultivars are needed for the diverse environments in West Asia to improve rural livelihoods. This study was conducted to determine the performance of elite wheat breeding lines developed by CIMMYT, to analyze their stability for grain yield across diverse environments, and to identify superior genotypes that could be valuable for varietal release. Genetically diverse 196 advanced breeding lines were evaluated across different sites in Afghanistan. Grain yield, days to heading and plant height were analyzed. Genotypic superiority for grain yield was determined using genotype and genotype × environment (GGE) biplot analysis. The experimental genotypes showed arrays of variation for grain yield in each year, with mean values ranging from 3908 to 7209 kg/ha. A set of 20 experimental genotypes superior to the check based on their high mean yield and stability across environments as assessed by the GGE rank was identified. The most stable high yielding genotypes were HD 2687; Elvia/5/Cndo/R143//Ente/Mexi75/3/AE. sq./4/2*Oci; Quaiu; Whear/Vivitsi//Whear; Kiritati/2*Trch; Waxwing; Munal#1; Whear//Inqalab 91*2/Tukuru and Snb//Cmh79A.955/3*Cno79/3/Attila/4/Chen/A.sq.(Taus)//Bcn/3/2*Kauz. These superior genotypes also had acceptable maturity and plant height. The findings of this study provides information on adaptation of the internationally important wheat genotypes, valuable for wheat improvement program in Afghanistan and its neighbouring countries in West, Central and South Asia.
Authors:S. Aggarwal, A. Almaula, P. Khodade, A. Parab, R. Duggal, C. Singh, A. Rawat, G. Chourasiya, S. Chitambar, and H. Jain
K-factors (= certified isotope ratio/observed isotope ratio) are determined for the isotope abundance measurements of uranium and plutonium by thermal ionisation mass spectrometry. An mdf of 0.07% and 0.18% per mass unit differing by a factor of about 3, is obtained for uranium and plutonium, respectively, employing double rhenium filament assembly in the ion source and Faraday cup as the detector using the presently available isotopic reference materials of uranium and plutonium.
Authors:S. L. Krishnamurthy, S. K. Sharma, D. K. Sharma, P. C. Sharma, Y. P. Singh, V. K. Mishra, D. Burman, B. Maji, B. K. Bandyopadhyay, S. Mandal, S. K. Sarangi, R. K. Gautam, P. K. Singh, K. K. Manohara, B. C. Marandi, D. P. Singh, G. Padmavathi, P. B. Vanve, K. D. Patil, S. Thirumeni, O. P. Verma, A. H. Khan, S. Tiwari, M. Shakila, A. M. Ismail, G. B. Gregorio, and R. K. Singh
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.
Authors:B. Kumar, K.S. Hooda, R. Gogoi, V. Kumar, S. Kumar, A. Abhishek, P. Bhati, J.C. Sekhar, K.R. Yathish, V. Singh, A. Das, G. Mukri, E. Varghese, H. Kaur, V. Malik, and O.P. Yadav
Maydis leaf blight (MLB), a serious foliar fungal disease of maize, may cause up to 40% losses in yield. The present studies were undertaken to identify the stable sources of MLB resistance, its inheritance study, and testing of MLB resistance linked markers from diverse background in the Indian adapted tropical maize genotypes. A set of 112 inbred lines were screened under artificially created epiphytotics conditions at three hotspot locations. Analysis across multi-locations revealed significant effects of genotypes and environments, and non-significant effects due to genotypes × environment interaction on disease incidence. A total of 25 inbred lines with stable resistance were identified across multi-locations. Inheritance of resistance was studied in six F1s and two F2s of resistant and susceptible parents. The null hypothesis of segregation of resistance and susceptible for mono and digenic ratios in two F2 populations was rejected by Chi-square test. The non-significant differences among the reciprocal crosses depicted the complete control of nuclear genome for MLB resistance. Partial dominance in F1s and normal distribution pattern in F2s of resistant and susceptible parents suggested polygenic nature of MLB resistance. Correlation studies in F2 populations exhibited significant negative correlation between disease score and days to flowering. Five simple sequence repeats (SSRs) markers, found associated to MLB resistance in different studies were unable to differentiate amongst MLB resistance and susceptible parents in our study. This emphasizes the need of fine mapping for MLB resistance in Indian germplasm. The identified stable sources of resistance and information on inheritance study can be used further in strengthening of resistance breeding against MLB.