International Letters of Natural Sciences Vol. 23

Abstract: Biofertilizers are the special formulation of specific beneficial microorganisms that promote the growth of plant crops by converting the unavailable form of nutrients into available form. Here, the effect of heavy metal stress on antioxidant enzymes were studied in Clitoria ternatea L. leaves. Clitoria ternatea L. plant was grown for 30 days and the heavy metal mercuric chloride was sprayed after 10 days from the date of planting. Effect of mercuric chloride was observed in treated plants. The selected plant Clitoria ternatea L. was grown under mercuric chloride treatment in a specified concentration 1 µg/10 ml. The control plant maintained without the treatment of mercuric chloride. Antioxidant effect of mercuric chloride was measured under controlled and treated conditions. The selected plant Clitoria ternatea L. was grown under mercuric chloride in treatment. Further it increases H₂O₂ content and the antioxidant enzyme activities such as superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) were observed in mercuric chloride treated plants when compared with control. Here mercuric chloride was accumulated more in matured leaves. The results are discussed with the literature.

Abstract: Tinchuley (Latitude: 26.89748 N, Longitude: 88.23268 E) is a remote hamlet located close to Darjeeling which can be reached through a drive of 32 kilometers. Takdah Cantonment (Latitude: 26.89745 N, Longitude: 88.23265 E) is a settlement located in Darjeeling district, West Bengal, India. It is one of the upcoming tourist centers of the Darjeeling hills, around 4 km. from Tinchuley. The winding roads, tall pine and fir trees, intruding packs of cloud and warm and hospitable people makes it an ideal destination for people looking to escape from the hectic lifestyle of the city. The main objective of the present research work was to construct the social, environmental, cultural and economic framework of Tinchuley and Takdah Cantonment area and to highlight the proposals for sustainable management policies of those ecologically sensitive zones. The study was done in May, 2014 by visiting Tinchuley and Takdah and the information was gathered through field survey and direct contact with common people and authorized centers of the regions. Surveys on the agriculture, horticulture, livestock, water management, education, culture, health, waste management, transport and biodiversity were done in these areas. Tinchuley and Takdah have become the prominent tourist spots of West Bengal for pleasure trips, biological and geographical excursions and medical research works. In spite of getting so much attention in the recent time, the areas are 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 regions.

Abstract: Nanotechnology is a field that is burgeoning day by day, making an impact in all spheres of human life. Biological methods of synthesis have paved way for the “greener synthesis” of nanoparticles and these have proven to be better methods due to slower kinetics, they offer better manipulation and control over crystal growth and their stabilization. In this context we have investigated extracellular biosynthesis of silver nanoparticles (AgNP_s) using cell-free extract of Rhizopus spp.. Formation of AgNP_s was indicated by the change in the colour of the cellfree extract from yellow to dark brown under static condition after 48 hrs of incubation. Characterization of AgNP_s was carried out by UV-Vis Spectroscopy which gave sharp plasmon resonance peak at 429 nm corresponding to spherical shaped nanoparticles. Transmission electron microscopy (TEM) micrograph showed formation of well-dispersed AgNP_s in the range of 25-50 nm. Scanning electron microscopy (SEM) showed the particles to be uniformly dispersed without agglomeration with smooth morphology. EDS showed the presence of elemental silver at 3kev. X-ray diffraction (XRD)-spectrum of the AgNP_s exhibited 2θ¸ values corresponding to nanocrystal. These biosynthesized AgNP_s were used to study their antimicrobial activity against Multi-drug resistant (MDR) E. coli strains, by Agar diffusion method. Zone of inhibition was measured. Synthesis of nanosized particles with antibacterial properties, which are called "nanoantibiotics", is of great interest in the development of new pharmaceutical products.

Abstract: Field experiments were conducted from July to November during the 2012 and 2013 cropping seasons, at the Research Farm, University of Agriculture, Makurdi, Nigeria, to evaluate the yields of two newly introduced sesame varieties (Ex Sudan and SN 603) against the commonly grown variety “E-8” under intercropping with maize variety ‘Oba 98’. The trial area consisted of a total of seven treatments, replicated three times in a randomized complete block design. The results showed that, though maize yield was not significantly (P ≤ 0.05) affected by intercropping with sesame varieties, however, intercropped yield of sesame variety ‘Ex Sudan’ was significantly (P ≤ 0.05) greater by 26.8 % and 25.6 % respectively, in years 2012 and 2013, compared to that obtained from intercropped sesame variety ‘SN 603’, and by 19.5 % and 20.9 % respectively, in years 2012 and 2013, compared to that produced from intercropped popular sesame variety ‘E-8’. Intercropping maize variety ‘Oba 98’ with sesame variety ‘Ex Sudan’ gave the highest total intercrop yield, greatest biological efficiency with a relative yield total values of 0.87 and 0.91 respectively, in 2012 and 2013. The combination also recorded the highest land equivalent ratio (LER), highest land equivalent coefficient, highest area x time equivalent ratio (ATER), highest total monetary returns (N584,200 and N588,600 respectively, in years 2012 and 2013) and highest monetary equivalent ratio (MER). The implication of study showed that sesame variety ‘Ex Sudan’ performed best and could therefore be recommended as a potential replacement for the popular variety ‘E-8’ under intercropping with maize variety ‘Oba 98’ in Makurdi, Nigeria.

Abstract: Plant growth and physiological response of sesame (Sesamum indicum L.) were studied in controlled environment using normal soil and indigenous Vesicular-arbuscular mycorrhiza (VAM) fungi treated soil. The seedlings of Zea mays were inoculated with Giguspora species of VAM (Glomus fasiculatum) and the inoculum was multiplied with help of Zeamays seed bed. Sesame seeds were then inoculated into the bed and it was found that the plant height, shoots lengths, roots, biomass of shoot and roots were considerably increased in the mycorrhizal plants. The effect of VAM infection was assessed in pot experiment. In this comparative study, specific mycorrhizal fungi had consistent effects on various growth parameters such as the number of leaves, number of roots, shoot length, biomass of shoot and roots and biochemical parameters were observed at various time intervals by statistical analysis using two way ANOVA, it was confined with mycorrhizal and non-mycorrhizal infected plants. It was found that the ability of isolates to maintain the plant growth effectively in the case of mycorrhizal seedlings shows a maximum absorbtion of 0.77 ±0.2, shoot length is about 8.34 ±0.2, count of root and leaves are about 8.10 ±0.3, 5.6 ±0.3 respectively under mycorrhizal infection in 30days of analysis and had a positive effect on the growth at all intervals. Biochemical analysis were carried out to estimate the total chlorophyll, chrophyll A, chlorophyll B and Carotenoids contents and it was analyzed to be 9 ±0.5 mg/g, 8.3 ±0.5 mg/g, 3.6 ±0.5 mg/g, 4 ±0.3 mg/g respectively. At the 30^th day of analysis for the mycorrhizal plants, it was found to be high in mycorrhizal seedlings which shows the symbiosis had improved the nutrient uptake of cultivated plants. Nevertheless G. fasiculatum was found to be the most efficient fungus and exhibited the highest levels of mycorrhizal colonization, as well as the greatest stimulation of physiological parameters.

Abstract: Chromium is a heavy metal; this element is considered as an environmental hazard. Toxicity effects of chromium on growth and development of plants including inhibition of germination process decrease of growth and biomass of plant. The aim of this research is to study accumulation of Chromium along with nutrients and its effect on the growth of Paddy plant (Oryza sativa L). Thus, paddy seedlings grown in petriplates lined with filter paper undergoing, different treatments of Cr (0, 2.5, 5, 10, 25, 50, 75, 100 and 200 mg/L). After one week seedlings were removed and morpho physiological parameters like root length, shoot length and dry weight of plants and Biochemicals ,accumulation of nutrients along with Cr in roots and shoots were determined. The results indicated that the concentrations more than 100 mg/L chromium cause the reduction of morphophysiology parameters in the treatment plants rather than control plant and Cr addition in the cultures caused enhancement of chromium content in roots and shoots of plant seedlings. Similarly the biochemicals and nutrient accumulation also affected by increasing concentrations of chromium. It was also noted that accumulation of chromium in the roots was much higher than the shoots of the seedlings under treatment.