Deb Prasad Ray

Start codon targeted (SCoT) polymorphism reveals genetic diversity in wild and domesticated populations of ramie (Boehmeria nivea L. Gaudich.), a premium textile fiber producing species

Twenty-four start codon targeted (SCoT) markers were used to assess genetic diversity and population structure of indigenous, introduced and domesticated ramie (Boehmeria nivea L. Gaudich.). A total of 155 genotypes from five populations were investigated for SCoT polymorphism, which produced 136 amplicons with 87.5% polymorphism. Polymorphism information content and resolving power of the SCoT markers were 0.69 and 3.22, respectively. The Indian ramie populations exhibited high SCoT polymorphism (> 50%), high genetic differentiation (GST = 0.27) and moderate gene flow (Nm = 1.34). Analysis of molecular variance identified significant differences for genetic polymorphism among the populations explaining 13.1% of the total variation. The domesticated population exhibited higher genetic polymorphism and heterozygosity compared to natural populations. Cluster analysis supported population genetic analysis and suggested close association between introduced and domesticated genotypes. The present study shows effectiveness of employing SCoT markers in a cross pollinated heterozygous species like Boehmeria, and would be useful for further studies in population genetics, conservation genetics and cultivar improvement.

Rapid estimation of compost enzymatic activity by spectral analysis method combined with machine learning

The aim of this study was to investigate the feasibility of using visible near-infrared (VisNIR) diffuse reflectance spectroscopy (DRS) as an easy, inexpensive, and rapid method to predict compost enzymatic activity, which traditionally measured by fluorescein diacetate hydrolysis (FDA-HR) assay. Compost samples representative of five different compost facilities were scanned by DRS, and the raw reflectance spectra were preprocessed using seven spectral transformations for predicting compost FDA-HR with six multivariate algorithms. Although principal component analysis for all spectral pretreatments satisfactorily identified the clusters by compost types, it could not separate different FDA contents. Furthermore, the artificial neural network multilayer perceptron (residual prediction deviation=3.2, validation r(2)=0.91 and RMSE=13.38 μg g(-1) h(-1)) outperformed other multivariate models to capture the highly non-linear relationships between compost enzymatic activity and VisNIR reflectance spectra after Savitzky-Golay first derivative pretreatment. This work demonstrates the efficiency of VisNIR DRS for predicting compost enzymatic as well as microbial activity.

Assessment of organochlorine pesticide residues in Indian flue-cured tobacco with gas chromatography-single quadrupole mass spectrometer

Presence of pesticide residues in tobacco increases health risk of both active and passive smokers, apart from the imminent potential health problems associated with it. Thus, monitoring of pesticide residue is an important issue in terms of formulating stringent policies, enabling global trade and safeguarding the consumer’s safety. In this study, a gas chromatography-single quadrupole mass spectrometry (GC-MS) method based upon quantifier-qualifier ions (m/z) ratio was employed for detecting and assessing ten organochlorine pesticide residues (α-HCH, β-HCH, γ-HCH, δ-HCH, 2,4-DDT, 4,4-DDT, endrin, α-endosulfan, β-endosulfan and endosulfan sulphate) in 152 flue-cured (FC) tobacco leave samples from two major tobacco growing states, Karnataka and Andhra Pradesh, of India. In the majority of samples, pesticide residue levels were below the limit of quantification (LOQ). In few samples, pesticide residues were detected and they found to comply with the guidance residue levels (GRL) specifications of the Cooperation Center for Scientific Research Relative to Tobacco (CORESTA). Detection of the phase out pesticides like DDT/HCH might be due to transfer of persistent residues from the environmental components to the plant. This is the first report on these ten organochlorine pesticide residues in Indian FC tobacco.

Screening of phosphorus solubilizing bacteria from tea rhizosphere soil based on growth performances under different stress conditions

Rhizospheric soil from tea [Camellia sinensis L.] was screened for the presence of phosphate solubilizing bacterial populationin-vitro where eighteen isolates were initially selected based on their growth characteristics. These isolates were further screened based on their growth performances under different stress conditions like growth temperature (15, 20, 25, 30 and 35°C), pH of growth medium (4 and 5.4), six Al concentrations using AlCl3 (2.5, 5, 7.7, 10, 25 and 50 mM) and desiccations with five concentrations of polyethylene glycol 6000 (0, 20, 30, 40 and 50%). A score sheet was developed for screening the efficient PSB strains which can tolerate stress by giving equal weightage to their growth performance under different stress conditions. A total of 11 PSB isolates were finally selected and further study is warranted for inoculating these isolates for increasing P nutrition for tea crop.

Biomarkers: A tool for monitoring pesticide pollution

The presence of xenobiotics in the environment always represents a risk for living organisms. Thus, there is a need to detect toxicity in the organism, and the concept of intoxication is related to specific organ alterations and clinical symptoms. Moreover, the relationship between the toxic levels within the organism and the toxic response is rather complex and has a difficult forecast because it depends on several factors, namely toxicokinetic and genetic factors. One of the methods to quantify the interaction with xenobiotics and its potential impact on living organisms, including the human being, is monitoring by the use of the so-called biomarkers. Biomarkers are used to detect the effects of pesticides before adverse clinical health effects occur. Pesticides and their metabolites are measured in biological samples, serum, fat, urine, blood, or breast milk by the usual analytical techniques. Biochemical responses to environmental chemicals provide a measure of toxic effect. A widely used biochemical biomarker, cholinesterase depression, measures exposure to organophosphorus and carbamate insecticides. Techniques that measure DNA damage (e.g., detection of DNA, protein and haemoglobin adducts) provide a powerful tool in measuring environmental effects. Determination of cytogenetic markers help in of monitoring populations occupationally or environmentally exposed to known or suspected mutagenic-carcinogenic agents. Thus suitable bioindicators, containing specific biomarkers hold the future trend of environmental monitoring.

Distribution of different forms of potassium in some coastal soils of West Bengal

The research work with a view to evaluate the status, availability, fixation, releasing and supplying behaviour of potassium for a meaningful K-fertilizer management strategy for sustainable crop production in the coastal soils of West Bengal. Forty surface (0-15 cm) soil samples representing the coastal soils of West Bengal were used for assessing the important physical and physicochemical properties and distribution of different forms of potassium. Total K and lattice K content of the soils were high ranging between 1.0 to 2.74 and 0.93 to 2.60%, respectively. Non-exchangeable, available, exchangeable and water soluble K contents of the soils varied from 534 to 1050, 68.81 to 284.77, 58.65 to 232.50 and 10.16 to 52.27 mg/kg contributing 3.84 to 6.32, 0.53 to 1.23, 0.45 to 1.02 and 0.08 to 0.22% towards total K, respectively. The overall soils were high in available, non-exchangeable and mineral K status. Based on the district wise average values of the different forms of K, the soils were in the order: Medinipur East > North 24 Parganas> South 24 Parganas. Different forms of soil K had highly significant positive correlation with pH and EC. Non-exchangeable K was significantly and positively correlated with organic carbon and CEC. Available K, exchangeable K and water soluble K had significant negative correlation with sand. All the forms of soil potassium were interrelated, indicating the existence of a dynamic equilibrium among them.

Evaluation of chemical and biological indices for carbon and nitrogen mineralization of various organic matters used in tea garden

The objective of this study was to evaluate the performance of chemical and biological indices to predict carbon and net nitrogen mineralization from a range of organic amendments that differed in their total carbon and nitrogen and the carbon quality. Three decomposed materials i.e. vermi compost (VC), farm yard manure (FYM), poultry manure (PM) and four un-decomposed materials i.e. raw cow dung (RCD), fish meal (FM), tannery waste (TW) and mustard cake (MC) were used for the experiment. Carbon mineralization was determined using alkali traps. Aerobic nitrogen mineralization was estimated using incubation and leaching method, whereas, anaerobic N-mineralization was done under waterlogged condition at 40oC. It was observed that water soluble organic carbon (WSOC) had significant correlation with C-mineralization (r=0.885**) and net aerobic N-mineralization (r=0.805*). Linear regression analysis also exhibited that WSOC had a very high linear relation with C-mineralization (r2=0.7835) and net N-mineralization (r2=0.649). Biological parameter i.e. 7 days anaerobic N-mineralization (ANI7) at high temperature exhibited significant correlation with C-mineralization (r=0.960**) and net aerobic nitrogen mineralization (r=0.855*). Net N-mineralization (aerobic) when regressed against anaerobic nitrogen index i.e. ANI-7, ANI-14 and ANI-21, R2 value of 0.733, 0.945 and 0.960 were found, respectively, indicating that anaerobic nitrogen mineralization index can be a useful tool for predicting nitrogen mineralizing capacity of various organic matters.

Exploration of Profitability in The Cultivation of Ramie (Boehmeria nivea L. Gaudich.) Fibre for Sustaining Rural Livelihood

Ramie or (Boehmeria nivea L. Gaudich.) is one of the most valuable bast fibre yielding crops of the world. Ramie fibre is much more superior than the other commonly used plant fibres like jute, cotton, flax, etc. in terms of bundle tenacity, wet strength, fineness, ultimate fibre length and the length to breadth ratio. It is one of the strongest but stiffest bast fibre due to its high cellulose to hemicellulose ratio which favours a high degree of cellulose crystallinity. Besides having the unique physical properties, its silklike appearance and anti-microbial property of the fibres as well as the medicinal value and antioxidant property of the ramie leaves make the plant utmost valuable in the International market. China is the chief ramie producer followed by Brazil and Philippines. In India there is a huge scope to exploit this fibre economically to get maximum benefit. The sandy loam soil with slopping land and hot-humid weather conditions that are required for ramie cultivation is available in the North Eastern parts of India. The foothills of Himalaya and the Brahmaputra valley of Assam, along with Western Ghats and Arunachal Pradesh have great natural resource to promote ramie cultivation. There is a great demand of ramie fibre in the market but the production is not enough to meet the need. This is an opportunity for the Indian farmers to start ramie cultivation in a wide range besides the regular cultivation of jute, cotton, mesta, flax, sisal, etc. As ramie has an inherent property to tolerate a wide range of temperature, soil and climatic factors, it isn’t difficult to cultivate ramie in a large scale. Moreover, ramie being a perennial crop helps in soil conservation and can also be intercropped with other plants to get the economical benefit of both the crops. Scientific cultivation of ramie, therefore, can pave a new path for sustaining rural livelihood.

A New Protocol for Extraction of Galactomannan Gum from Dhaincha (Sesbania aculeata L.) Seeds

The polysaccharides or gums are derived from the endosperm of various plants, mainly from Leguminosae seeds, where they function as reserve materials utilized during germination. Most of these polysaccharides share basic structural similarities, known as galactomannans. Galactomannans are reserve polysaccharides consisting mainly of the monosaccharides mannose and galactose units. The mannose-elements form a linear chain consisting of (1→4)-β-D-mannopyranosyl residues, with (1→6) linked α-D-galactopyranosyl residues as side chain at varying distances, depending on the plant of origin. Dhaincha (Sesbania aculeata) seed contains hydrocolloidal polysaccharides composed of galactans and mannans units combined through glycosidic linkages very much similar to that obtained from guar gum having D-galactose-D mannose ratio of 1: 22. In this paper, a simple method of extraction have been elucidated which not only reduces and cost and energy involvement but also effective to yield sufficient gum constituents from the seeds.

Reviewing Mathematical Models for Pesticide Leaching Studies

Leaching is an unavoidable phenomenon associated with the pesticide applications. Leaching of pesticide does not only indicate the efficiency of a pesticide molecule, but also degree of the environmental contamination. Leaching is the process by which a pesticide molecule enters the soil-water ecosystem. Hence, to access the leaching behavior of a pesticide molecule, various models are used globally. This paper reviewed some globally adapted leaching models and tried to find the best fitted model for leaching study.