International Letters of Natural Sciences Vol. 22

Abstract: To compare the effect of NaCl, CaCl2 and their combinations on germination and early seedling growth stages of Lycopersicum esculentum L., were studied under pot experiments 2008. Results indicated that significant increases were recorded in percentage of germination, seedling fresh and dry weights, seedling length, water content, catalase activity and photosynthetic pigments (chlorophyll a, b and total chlorophylls as well as carotenoids) under the low level concentration (20 mM) of NaCl or CaCl and their combination (1:1). On other hand increasing salt concentration in nutrient solution caused significant decrease in all of these parameters. The great reduction occurred under high salinity level of NaCl (50 mM). Meanwhile, peroxidase activity increased significantly with increasing salinity levels from 20 mM to 50 mM of both applied salinity types. Besides, peroxidase activity under NaCl salinity showed a marked increase followed by NaCl + CaCl2 (1:1) and CaCl2 at 50 mM.

Abstract: This paper describes the fruiting phenology and avian frugivory of Streblus asper (Moraceae) in a mixed dry deciduous forest, Anaikatty hills, Western Ghats. Fruiting occurred during April-June. Nine species of birds were found to feed on the ripe fruits of this species. Bulbuls (3 species) belonging to Pycnonotidae, followed by two species of Myna (Sturnidae) made majority of the feeding visits and appear to be the major seed dispersers of this species

Abstract: Vibrio cholerae, the causative agent of Asiatic cholera, is a gram-negative motile bacterial species acquired via oral ingestion of contaminated food or water sources. Cholera has spread from the Indian subcontinent where it is endemic to involve nearly the whole world seven times during the past 185 years. V. cholerae serogroup O1, biotype El Tor, has moved from Asia to cause pandemic disease in Africa and South America during the past 35 years. A new serogroup, O139, appeared in south Asia in 1992, has become endemic there, and threatens to start the next pandemic. The facultative human pathogen V. cholerae represents a paradigm that evolved from environmental non-pathogenic strains by acquisition of virulence genes. The major virulence factors of V. cholerae, cholera toxin (CTX) encoded by the ctxAB genes residing in the genome of filamentous lysogenic bacteriophage (CTXɸ) and toxin coregulated pilus (TCP) encoded by vibrio pathogenicity island (VPI). CTX, a potent stimulator of adenylate cyclase, causes the intestine to secrete watery fluid rich in sodium, bicarbonate, and potassium, in volumes far exceeding the intestinal absorptive capacity, by ADP-ribosylation of the alpha subunit of the GTP-binding protein. Thus intestinal infection with V. cholerae results in the loss of large volumes of watery stool, leading to severe and rapidly progressing dehydration and shock. Without adequate and appropriate rehydration therapy, severe cholera kills about half of affected individuals. Today, cholera still remains a burden mainly for underdeveloped countries, which cannot afford to establish or to maintain necessary hygienic and medical facilities. During the last three decades, intensive research has been undertaken to unravel the virulence properties and to study the epidemiology of this significant human pathogen. This review provides an overview of the role of CTX in the occurrence of this disease in humans.

Abstract: Effect of EMS (ethyl methane sulphonate) on induced morphological mutants and chromosomal variation in cowpea was studied using five different doses of mutagen along with a control in randomized blocked design with three replications. The morphological mutants there are two types of viable and chlorophyll mutants. Viable mutant contains tall, dwarf, early maturity, late maturity, leaf mutants pod mutant and flower mutants. The frequency of chlorophyll mutant contains albino, xantha and viridis. This concentration can damage or modify important components of plant cells and have been reported to affect the morphology, anatomy, biochemistry and physiology of plants differentially depending on the concentration level. These effects include changes in the cellular structure and metabolism of the plants e.g., dilation of thylakoid membranes, alteration in photosynthesis, modulation of the antioxidative system and accumulation of phenolic compounds. The morphological and chromosomal variation was found to be mutagen sensitive in somatic cells of cowpea. It was found to increase with increasing the concentration of EMS in Cowpea plants. The chemical mutagen like ethyl methane sulphonate induces high frequency of chromosomal changes like anaphasic bridge; anaphasic laggard, anaphasic bridge and clumbing of chromosome were including control plants also observed.

Abstract: Our present study was aimed to detect the medicinal uses of the plant Murraya koenigii (L) Spreng belonging to the family Rutaceae by performing various studies such as Pharmacognostical, phytochemical and antibacterial activity, using seven different bacterial strains, which are harmful to human beings. The Murraya koenigii commonly known as “Curry leaf“ has been recognized in different systems of traditional medicines for the treatment of different diseases and ailments of human beings. The leaves of the plant are said to be cooling and stomachache. The study includes macroscopy, microscopy, preliminary phytochemical screening and antibacterial evaluation

Abstract: The present investigation has been carried out to study the anatomical features of root, rhizome, stem, leaf and petiole for evaluating the Oxystelma esculentum, an important medicinal plant used in the traditional systems of medicine. This study provides referential pharmaco-botanical information for correct identification of this plant.