International Letters of Natural Sciences Vol. 21

Abstract: Oryza sativa Linn. (rice) and Corchorus capsularis Linn. (jute) are the two major crops of the Bengal basin. Both rice and jute are generally grown in submerged flooded conditions, where arsenic bioavailability is high in soil. The consumers of the edible parts from both plants therefore face an inevitable source of exposure to arsenic, with consequent accumulation and toxicity. The objective of the study was to observe the in-vivo temporal variation of arsenic bioaccumulation in the different parts of O. sativa and C. capsularis. Rice plant specimens (Aman rice, Ratna variety) of different age groups (1, 2 and 3 months old) were analyzed in HG-AAS for absorbed arsenic content in different parts. The accumulation of arsenic remained significantly high in the initial phase of growth, but decreased with time. Amount of arsenic bioaccumulation followed the decreasing order: root > basal stem > median stem > apical stem > leaves > grains in all the three age groups of the rice plant samples. C. capsularis followed a trend of arsenic bioaccumulation similar to O. sativa. O. sativa had more accumulation potential than C. capsularis, but C. capsularis showed much higher efficiency of arsenic translocation in the above ground parts. This is the first ever report of time-dependent decrease in arsenic bioaccumulation in O. sativa and C. capsularis. The contamination level can reach the grain part in significant amount and can cause health hazards in more severely arsenic affected areas. Intensive investigation on a complete food chain is urgently needed in the arsenic contaminated zones for further risk assessments.

Abstract: The plant Justicia simplex D.Don is traditional herb, people used it in different diseases, they treat fever and burning of the body, strengthen the lungs, the teeth and stop vomiting. The plant exhibited more promising bacterial activity against various microorganisms. Hence, in the present study this plant is also tested against the dental pathogens. The plant was extracted from four different solvents was tested for the presence of phytochemicals in it. After analyzing, its antimicrobial activity is tested against fungi and bacteria. Then a dental carrier Streptococcus aureus, Klebsiella pneumonia, Escherichia coli and Pseudomonas aeruginosa which was collected from the K.S.R. Institute for Dental Science and Research. The isolates were used to check the activity against Justicia simplex D.Don. Based on the positive result obtained against various analyses, it is formulated successfully into a tooth paste. The present study on Phytochemical screening of Justicia simplex D.Don a valuable medicinal plant extract against Dental pathogens enables the use of this plant for the formulation of tooth powder against dental pathogens. The result is more effective against dental pathogens by herbal tooth powder

Abstract: This study was conducted to investigate toxic effects of Pb on growth and nutrient uptake in Black gram. Black gram was subjected to seven (5, 10, 25, 50, 75, 100 & 200 kg-1) levels of lead. Due to Pb toxicity, plant growth was adversely affected and relatively a severe reduction in root biomass was recorded. The Pb accumulation increased with the increase in lead concentrations. The uptake of different nutrients, i.e., N, P, K, Ca and Mg was reduced in black gram due to the lead treatment.

Abstract: The antibacterial activity of Eclipta alba against three gram positive and five gram negative bacterial strains was investigated. The fresh whole plants were collected from Chidambaram, Tamil Nadu. Petroleum ether, chloroform, ethyl acetate, acetone, methanol and aqueous extracts at different concentrations (1, 2, 5, 10 mg/ml) were used to investigate the antibacterial activity. NCCL standards were strictly followed to perform antibacterial disc susceptibility test using disc diffusion method. The extracts showed varying degree of inhibitory potential against all the tested bacteria. Methanol extract of the plant had higher inhibitory action against Staphylococcus aureus, Bacillus subtilis, Proteus mirabilis and Pseudomonas fluroescens.

Abstract: The miotic and meotic behaviour is considered to be one of the most dependable indices to estimate the potency of mutagen cytological aberrations in plants serve as an excellent monitoring system for the determination of mutagens that may cause a genetic hazard in the present study cluster bean contains 7 bivalents (24 = 14) for the present investigation the plant exposed to dolf concentration of 60, 80, and 100kr gamma rays and 0.4, 0.6 and 0.8 % Mm ( EMS ) the present study reveals various chromosomal aberration includes stickiness precocisus movement ,single and anaphasis bridge laggards and synchronized movement of chromosomes at anaphase

Abstract: In the present investigation the seeds of Pigeon pea (Cajanus cajan (L.) Millsp) were treated with different doses of gamma radiation (05KR, 10KR, 15KR, 20KR, 25KR, 30KR, 35KR, 40KR, 45KR, and 50KR) and concentration of Ethyl Methane Sulphonate (05mM, 10mM, 15mM, 20mM, 25mM, 30mM, 35mM, 40mM, 45mM, and 50mM) for studying seed germination, seedling height, (shoot and root), seedling injury, seedling vigour index, and seedling survival of plants at 30^th day. The seed germination percentage was decreased with increased in the concentration/doses when compared to control. The LD₅₀ (Lethal dose) value was determined based upon the seed germination percentage. The 50 percentage of seed germination and reduction was observed in 20KR of gamma rays and 25mM of EMS and it is considered as LD₅₀ value for both the treatments. The decrease in seed germination was more prominent with gamma rays than that of EMS treatments. The seedling parameters of gamma rays and EMS treated seedlings were progressively decreased with increase dose/concentration in all mutagenic treatments when compared to control. The maximum seedling parameters were observed in 05KR of gamma rays and 05mM of EMS. Minimum seedling parameters were observed in 50mM of EMS and 50KR of gamma rays respectively.