International Letters of Natural Sciences Vol. 33

Abstract: The nucleic acid content in different tissues such as brain, liver, kidney & testis of both control and copper sulphate (CuSO₄) exposed freshwater fish N. notopterus has been studied. The following observation is made in both control and copper sulphate (CuSO₄) exposed fish. The testis contain large amount of DNA in comparison to other tissues. The degree of DNA content in control and copper sulphate (CuSO₄) exposed fish testis >liver>brain>kidney. The RNA content also exhibited similar to that of DNA, having higher amount in the testis. The degree of RNA content in control and copper sulphate (Cuso4) exposed fish testis >liver>brain>kidney. The nucleic acid content of tissues get reduced under copper sulphate (CuSO₄) exposed in the male freshwater fish N. notopterus indicating copper sulphate as a pollutant effect the nucleic acid content in the tissue.

Abstract: Green revolution increased the food production enormously to feed the geometrically growing population. In India, the availability and affordability of fossil fuel based chemical fertilizers at the farm level have been ensured only through imports and subsidies. Dependence on chemical fertilizers for future agricultural growth would mean further loss in soil quality. The possibilities of water contamination and unsustainable burden of the fiscal system. The Government of India has been trying to promote an improved practice involving use of biofertilizers along with fertilizers. These inputs have multiple beneficial impacts on the soil and can be relatively cheap and convenient for use. The agricultural chemicals like pesticide and weedicides were being used to save the standing crop from the attack of pests and to boost crop production. At the same time the excess use of chemical fertilizers degraded the soil properties. In this context, the farmers are expecting for the cheapest and eco-friendly alternative for getting higher yield. Biofertilizers is only the alternative way to get more production without harmful to environment. So the effect of different doses of biofertilizer (Rhizobium) on germination studies of Fenu-greek seed germination percentage, seedling growth, fresh weight and dry weight, chlorophyll, protein and soluble sugar content has been studied in the laboratory condition. There parameters increased to application when biofertilizer compared to control.

Abstract: The current study was intended to evaluate abortifacient and antioxidant activity of Avicennia marina leaves extracts. Abortifacient activity was evaluated in rats, compared with standard drug (Mifepristone) and antioxidant activity was evaluated by using three free radicals (Superoxide, Hydroxyl and DPPH) compared with Ascorbic acid. The extracts were showed pre implantation loss, post implantation loss of implantations and decreased the survival ration of foetuses. Among all extracts hydroalcoholic extract showed better activity. The selected plant extracts showed concentration dependent percentage inhibition of free radicals. Among three extracts hydroalcoholic extract showed better activity with IC₅₀ values on superoxide, hydroxyl and DPPH radicals were 203μg, 237μg and 143μg. From the results obtained during the study it the hydroalcoholic extract was used for the isolation of pure compounds, and isolated the different compounds (β-sitosterol, Lupeol and Betulinic acid).

Abstract: Plant RNA interference has been a very well studied phenomenon since its discovery. We are well versed with the types of small noncoding RNAs that are prevalent in the plant systems and their pathways of biogenesis and subsequent actions. However, apart from model plant systems such as Arabidopsis and Oryza, very little information is available regarding the other members of the RNA interference machinery; specially Argonaute proteins which acts as the major stabilizing factor for execution of the interference. This work focuses on the exploration of the sequenced crop genomes available on the web using a hybrid approach of computational protein fishing and genome mining. The results indicate that this hybrid approach was successful in the identification of argonaute proteins in the crop genomes under study.

Abstract: RNA silencing is one of the important phenomenon in plant defense mechanism, it actively protect host plants against viral infections. Existing viruses must have developed counter defense strategies to survive this arms race. Such counter defense strategy is the viral silencing suppressor (VSRs) which have been reported to directly interfere with the various steps leading to the interference of viral RNAs. Most identified VSRs are multifunctional, besides being RNA-silencing suppressors, they often perform essential roles by functioning as coat proteins, helper components for viral transmission, replicases and movement proteins, proteases or transcriptional regulators. One such identified VSR is AC4 of Sri Lankan cassava mosaic virus strain. Trivial knowledge about the structure –function relationship of this VSR leads to this work, where we focus on the structure generation by modelling to identify the mode of interactions with the various effector molecules of the silencing pathways. Structural analyses have been performed to screen interacting residues. Results indicate conserved structural features which signify propensity of functional interactions and further shows that this VSR can be a potent tool for the analysis of RNA silencing mechanisms and the relationships between different silencing pathways and VSRs.

Abstract: Indoor environment is significant with respect to human health especially if it is concerned when the building is v. Aim of very old. In the present study was to assess the presence of airborne fungi at an old building in Kolkata India where lots of tourists are exposed every day. Residence of famous Nobel laureate poet Rabindranath Tagore (built in the 18th century and presently used as a famous museum) in Kolkata, West Bengal was selected for this study and the indoor fungi from different room of the museum were assessed by using exposure plate technique. Humidity, temperature, wind speed and illuminance were also measured by hygrometer, thermometer anemometer and lux-meter respectively. The fungal species isolated from the air samples of different rooms were Aspergillus sp., Penicillium sp., Paecilomyces sp., Trichoderma sp, Alternaria sp Verticillium sp, Fusarium sp, Cladosporium sp, Yeast, Curvularia sp. and Helminthosporium sp. among them, Aspergillus sp. (71.4% at monsoon at library), Penicillium sp (57% at summer at library), Paecilomyces sp.(91% at monsoon at manuscript room) are mostly dominated pathogens, which may harm the workers and visitors of the museum. No significant correlation among colony forming unit of fungi with illuminance, wind speed and temperature in the tested indoor environment was noted whereas, the humidity in indoor environment played a crucial (P<0.05) role. Round the year humidity control may be required for maintaining healthy environment.

Abstract: Forest cover in hills is essential to maintain environmental, economic and ecological balances. North Bengal accounts for 3,086 sq km (26 %) of the 11,876 sq km area of classified forests in the state, and for nearly 5,000 sq km (40 %) of all land under tree cover. Upper Chatakpur is one of the emerging ecotourism spots of north Bengal, located at an altitude of 7887 feet in Darjeeling district. It is a 180 years old ethnic village with 19 houses and a population of about 89, and at an altitude of 7887 ft. It is about 8 km. from Sonada (26° 57' N, 88° 16' E), 22 km. from Darjeeling (26° 2' N, 88° 15' E) and 72 km. from Siliguri (26° 42' N, 88° 25' E). Upper Chatakpur Village situated within Senchal Wildlife Sanctuary, Darjeeling. The sanctuary with an area of 38.88 sq. km has an elevation of 1500-2600 m. The survey work was done in December, 2014 by visiting upper Chatakpur village and the primary data were gathered through field survey and direct contact with common people and authorized centers of the region. Surveys on the topography, demography, agriculture, livestock, water management, education, culture, health, waste management, transport, biodiversity, human animal conflict were done in this area. Medicinal plant diversity was studied in the village area and information was gathered from the local forest department centre. Information regarding the transport system was collected from the local transport office and syndicate. Census report was collected from the Sonada Panchayat Office. Health and education information was collected from the local primary school and the local sub health centre. Information on sustainable agricultural practices and waste management policies is collected through surveys in the village houses and agricultural fields. Biodiversity of Senchal Wildlife Sanctuary was documented by visiting the forest areas. Pictorial documentation was done in every phase of study. In spite of getting so much attention in the recent time, the village is not adequately developed. There is an urgent need for implementing sustainable management systems in the areas for the betterment of the socio-environmental structures. Some of the possible management strategies have been suggested for maintaining the social, environmental, economic and ecological balance of the region.

Abstract: There is a worldwide search for the safe, effective and eco-friendly compounds of plant origin to combat the weed species and other pests which are responsible for the great impact on the growth and productivity of agricultural crops. In this present study, a comparison was made to evaluate the phytotoxicity potential of sequentially extracted solvent (hexane, ethyl-acetate, methanol) extracts of Parthenium hysterophorus L. (aerial parts) in vitro through bench-top seed germination assay (Vigna radiata L.). One-way analysis of variance (ANOVA) followed by Duncan’s multiple range test (DMRT) were done for statistical analysis of the data. The study reveals that germination, growth and vigour was significantly (P<0.05) reduced by ethyl-acetate and methanol extracts. The present study concluded that phytotoxicity of ethylacetate and methanolic crude extracts of Parthenium hysterophorus could be exploited as potential bioherbicide for future weed management programme and the development of bioherbicide for commercial use.