Physiochemical Responses of Stevia rebaudiana Bertoni Subjected to Sodium Chloride (NaCl) Salinity and Exogenous Salicylic Acid Application

Gesunde Pflanzen - Soil salinity is one of the ecological problems limiting plant growth and development, especially in semi-arid and arid regions where water availability is very limited. Stevia...     

Preparation, Characterization, and Environmental Application of Crosslinked Chitosan-Coated Bentonite for Tartrazine Adsorption from Aqueous Solutions

The preparation, characterization, and environmental application of crosslinked chitosan-coated bentonite (CCB) beads for tartrazine adsorption have been investigated. CCB beads were characterized by using Fourier transform infrared spectrophotometer (FTIR), scanning electron microscope (SEM), and Brunauer–Emmett–Teller (BET) surface area and Barrett–Joyner–Halenda (BJH) pore size distribution analyses were also determined. The values of pH of the aqueous slurry and pH of zero point charge (pH_ZPC) were almost equal. The adsorption at equilibrium of tartrazine was found to be a function of pH of the solution, stirring rate, contact time, and tartrazine concentration. The optimum conditions for tartrazine adsorption were pH 2.5, stirring rate of 400 rpm and contact time of 80 min. Pseudo-first-order and pseudo-second-order models were used to analyze the kinetics of adsorption with the latter found to agree well with the kinetics data, suggesting that the rate determining step may be chemisorption. The two most common isotherm models, Langmuir and Freundlich, were used to describe the adsorption equilibrium data. On the basis of Langmuir isotherm model, the maximum adsorption capacities were determined to be 250.0, 277.8, and 294.1 mg g^?1 at 300, 310, and 320 K, respectively. Desorption studies were carried out at different concentrations of EDTA, H₂SO₄, and NaOH. All desorbing solutions showed poor recovery of tartrazine.     

Retrospective Study on Seroprevalence of Borrelia burgdorferi Antibodies in Horses in Minnesota

To determine the seroprevalence of Borrelia burgdorferi antibodies in horses in Minnesota, the database of the Veterinary Diagnostic Laboratory, University of Minnesota, was searched over a 10-year period (May 2001 to May 2010). A total of 1,260 equine serum samples submitted by 112 veterinary clinics were tested using an indirect fluorescent antibody test. Samples with titers of ≥1:320 were considered positive. The average rate of seroprevalence was 58.7%, indicating high exposure of horses to B burgdorferi in Minnesota. Our results indicate that borreliosis should be considered as a differential in cases of horses with undiagnosed musculoskeletal or neurologic disease.     

Determination of optimum tapping date for gum arabic production in South Kordofan State, Sudan

Acacia senegal, the gum arabic producing tree, is the most important tree species for the livelihood of the people in South Kordofan State, Sudan. The objective of this study was to determine the optimum tapping date for gum arabic production in the study area. A randomized complete block design experiment with three replications was conducted at (Meari) area for two continuous growing seasons 2008/2009 - 2009/2010. The treatments comprised six tapping dates (1 Oct, 15 Oct, 1 Nov, 15 Nov, 1 Dec, and 15 Dec). Results showed highly significant differences (p < 0.001) in gum arabic yield (g\tree) in all pickings and in the total gum yield between the tapping dates. The results also showed that tapping of trees on 15 October and 1 November gave a higher yield compared to the other dates. The highest gum yield of 1086.6 and 661.2 g/tree was recorded on 15 October and 15 November, while the lowest gum yield of 297.9 g/tree was recorded when the trees were tapped on 1 October. The two highest-yield dates of tapping (15 Oct and 1 Nov) are recommended as the best time for tapping for gum arabic production in South Kordofan State. These results can be used to increase gum arabic production and farmer income in South Kordofan State.     

Extinction risk assessment of the world’s seagrass species

Seagrasses, a functional group of marine flowering plants rooted in the world’s coastal oceans, support marine food webs and provide essential habitat for many coastal species, playing a critical role in the equilibrium of coastal ecosystems and human livelihoods. For the first time, the probability of extinction is determined for the world’s seagrass species under the Categories and Criteria of the International Union for the Conservation of Nature (IUCN) Red List of Threatened Species. Several studies have indicated that seagrass habitat is declining worldwide. Our focus is to determine the risk of extinction for individual seagrass species, a 4-year process involving seagrass experts internationally, compilation of data on species’ status, populations, and distribution, and review of the biology and ecology of each of the world’s seagrass species. Ten seagrass species are at elevated risk of extinction (14% of all seagrass species), with three species qualifying as Endangered. Seagrass species loss and degradation of seagrass biodiversity will have serious repercussions for marine biodiversity and the human populations that depend upon the resources and ecosystem services that seagrasses provide.     

Seed protein fractions and amino acid composition in gram (Cicer arietinum)

Six chickpea strains were analysed for their protein content and various protein fractions. The protein content ranged from 20.9–25.27%. Albumin, globulin, prolamin and glutelin contents ranged from 8.39–12.31%; 53.44–60.29%; 3.12–6.89% and 19.38–24.40% respectively. Salt soluble proteins (albumin + globulin) and globulins resolved into 19–23 bands whereas albumin proteins resolved into 30–34 bands. The molecular weights of various polypeptides ranged from 10–91 kD. Amino acid analysis of total proteins revealed that glutamic acid was present in maximum concentration followed by aspartic acid and arginine. Just like other pulse proteins, chick pea proteins were also found deficient in sulphur containing amino acids.     

Biochemistry of Fruit Ripening of Guava (Psidium guajava L.): Compositional and Enzymatic Changes

Changes in chemical composition and the activities of hydrolytic enzymes during four different stages of maturity, viz. mature green (MG), color turning (CT), ripe (R), and overripe (OR), have been studied in guava fruits cv. Banarsi Surkha. Chlorophyll content decreased while carotenoid content increased during ripening. Starch content decreased with concomitant increase in alcohol-soluble sugars. Cellulose, hemicellulose, and lignin also decreased up to ripe stage, while pectin continued to decrease up to OR stage. PG (polygalacturonase) and cellulase exhibited progressive increase in activity throughout ripening, whereas pectin methyl esterase (PME) activity increased up to CT stage and decreased at R stage. The activities of alpha-amylase and beta-amylase decreased significantly with ripening. The most notable metabolic changes occurred between MG and CT stage, implying that for improved postharvest handling, guava fruits may be harvested at CT stage.     

Relative abundance and damage by target and non-target insects on Bollgard and BollgardII cotton cultivars

Bollgard^® and BollgardII^® cotton cultivars were evaluated for their efficacy for control of bollworms and their effects on sucking insects and the abundance of natural enemies under bollworm insecticide protected and non-insecticide protected field conditions during the 2004 and 2005 cropping seasons. Bollgard cultivars are genetic transforms that produce Cry1Ac toxins from Bacillus thuringiensis (Bt) to control American bollworm, Helicoverpa armigera. Second generation BollgardII cultivars contain 2 toxins, Cry1Ac and Cry2Ab, and are more effective in controlling a broader range of caterpillar species. Bollgard cultivars were free of H. armigera damage until harvest under insecticide protected as well as non-protected conditions. Both BollgardII and Bollgard cultivars were infested with larvae of spotted bollworm, Earias vitella, and spiny bollworm, Earias insulana, at later crop growth stages. Neither BollgardII nor Bollgard cultivars were free of square (fruiting body), open boll and loculi damage. Bollworm damage did not reach economic threshold levels up to harvest. Densities of sucking insects (Amrasca biguttula biguttula, Bemisia tabaci, Aphis gossypi, and Thrips tabaci), of the foliage feeder Myllocerus undecimpustulatus and of predators (Chrysoperla spp., Orius spp., Coccinella spp., Brumus spp., Vespa spp., Lycosa spp., and Aranews spp.) were similar on Bollgard, BollgardII and conventional cultivars. The time of the first appearance of bollworms, sucking insects and predators on Bt cotton did not vary from conventional cotton varieties. Insecticidal protection based on economic threshold levels resulted in significant reductions in bollworm damage on conventional cultivars.     

Constituents from fruits of Cupressus sempervirens

Two new phenolic glycosides (1, 2), along with fourteen known compounds (3–16) have been isolated from the fruit of Cupressus sempervirens. The structures of these compounds were determined by spectroscopic analysis and were evaluated for their inhibitory activity against glycogen phosphorylase and glucose-6-phosphatase enzymes. Compounds 14 showed a moderate inhibition against glucose-6-phosphatase and 15 against glycogen phosphorylase enzymes.     

Response of a freshwater air-breathing fish, Clarias batrachus to salinity stress: an experimental case for their farming in brackishwater areas in Andaman, India

The study was conducted to assess the effects of salinity on growth and biochemical composition of freshwater catfish, Clarias batrachus. A static nonrenewable acute toxicity bioassay test was conducted and LC₅₀ of salinity for 96-h exposure to the fingerling (14.5 cm) was 12.52 ‰. Based on these results, two sublethal salinity levels, viz. 4 and 8 ‰ were selected to study the long-term effects of salinity on C. batrachus for a period of 90 days. From the study, it was found that growth and survival rate were less in saline water (4 and 8 ‰). Maximum growth and survival were recorded in freshwater (0 ‰ salinity) and subsequently at 4 and 8 ‰. To assess the biochemical alteration, few important biomarkers were estimated. At the end of 90 days rearing period, glucose level in the brain and blood of C. batrachus was found to decrease with salinity. The level of liver and muscle glycogen in the fish reared at 4 ‰ was lower than that of control. Ascorbic acid in all organs under study was found to decrease with increasing salinity, which was attributed to stress mitigation effect of vitamin C. Acetylcholine esterase (AchE) activity recorded a gradual decrease with increasing salinity. Metabolic enzymes, alkaline phosphatase (ALP) activity and adenosine triphosphosphtase (ATPase) activity also reduced both in liver and muscle tissues with increasing salinity. From the present investigation, it can be concluded that exposure to higher salinity significantly (P < 0.01) affects the growth and physiological response of Clarias batrachus.