Drought stress-induced oxidative stress and antioxidative responses in four wheat (Triticum aestivum L.) varieties

Drought stress was imposed on four varieties of wheat (Triticum aestivum L.), Mohan Wonder (MW), Kedar (K), Gayetri (GY) and Gandhari (GN), for 3, 6 and 9 days. The activities of all five tested antioxidative enzymes, peroxidase, ascorbate peroxidase, catalase, glutathione reductase and superoxide dismutase, were enhanced initially in varieties K and GN, whereas in MW and GY, catalase and superoxide dismutase showed a decrease in activity at all periods of drought stress. Peroxidase and glutathione reductase activities increased even on the ninth day of stress in K and GN, but all other activities showed a decrease after 3 days of stress. H₂O₂ accumulation increased with drought stress, but in K and GN there was decrease during prolonged drought stress. Lipid peroxidation increased significantly due to drought stress, which was higher in the case of MW and GY. Proline, phenol and ascorbate content increased with period of drought stress. Carotenoid accumulation also increased initially. Total chlorophylls showed a general decrease during drought stress. The results of this study indicate that two of the varieties, MW and GY, are susceptible to drought stress, whereas the other two, K and GN, are tolerant, with peroxidase and glutathione reductase being most important in conferring tolerance.     

Effect of composting on extractability and relative availability of heavy metals present in Calcutta municipal solid waste

How composting affects heavy metal content is largely unknown. Accordingly, we investigate the total content of six heavy metals, Cd/Zn ratio and the Zn-equiv, the relative availability and fractionation study to assess the suitability of compost derived out of those for environmental concerns. During composting, total metal content increased but their RA decreased. As a result of composting bioavailable form of metals also decreased. High significant correlations between different forms of heavy metals content and degree of humification were found for all the elements. Composting increases humic acid content than fulvic acid. This transformation is mainly responsible to serve as binding agent for metal thereby moderating the rapid metal mobilization.     

Prediction of soil nutrient content via pXRF spectrometry and its spatial variation in a highly variable tropical area

Precision Agriculture - Precision agriculture provides detailed information on the spatial variability of soil properties, including nutrient content, allowing for local-specific decision making....     

Dicamba resistance: enlarging and preserving biotechnology-based weed management strategies

The advent of biotechnology-derived, herbicide-resistant crops has revolutionized farming practices in many countries. Facile, highly effective, environmentally sound, and profitable weed control methods have been rapidly adopted by crop producers who value the benefits associated with biotechnology-derived weed management traits. But a rapid rise in the populations of several troublesome weeds that are tolerant or resistant to herbicides currently used in conjunction with herbicide-resistant crops may signify that the useful lifetime of these economically important weed management traits will be cut short. We describe the development of soybean and other broadleaf plant species resistant to dicamba, a widely used, inexpensive, and environmentally safe herbicide. The dicamba resistance technology will augment current herbicide resistance technologies and extend their effective lifetime. Attributes of both nuclear- and chloroplast-encoded dicamba resistance genes that affect the potency and expected durability of the herbicide resistance trait are examined.     

Genotypic diversity in Fusarium pseudograminearum populations in Australian wheat fields

Despite being closely related to Fusarium graminearum, which has been extensively characterized in many countries around the world, the population biology of Fusarium pseudograminearum, the main causal agent of crown rot of wheat in Australia and many other wheat‐growing regions, has been comparatively poorly studied to date. A simple sequence repeat analysis of 163 F. pseudograminearum isolates from three field sites in NSW, Australia identified 128 distinct multilocus genotypes. Observed genetic diversity within fields was high, whilst genetic variation between fields was low. Across all fields genetic linkage disequilibrium was detected, but of the three individual fields, only one also displayed linkage disequilibrium. These results indicate that the isolates obtained were part of the same, highly diverse, population. However, this population may not be freely interbreeding. Whilst isolation incidence of F. pseudograminearum was found to be spatially aggregated within fields, spatial aggregation of genotypes within fields was weak. The study suggests that processes influencing population dynamics may operate at a scale larger than the narrow geographical scale covered in the fields sampled.     

Preliminary Studies on Cryopreservation of Vegetative Thalli of Some Economically Important Seaweeds of India

The effects of cryoprotectants and their concentrations, prefreezing temperature, equilibration time, thawing temperature, and the regenerative efficacy of cryopreserved vegetative thalli (apical tips) of Gracilaria corticata J. Agardh., Ulva lobata Duetzing, and Hypnea musiformis (Wulfar) Lamouroux were evaluated. The apical tips were suspended in various cryoprotective solutions and slowly cooled to ?40?C over a period of 4 h. After the slow cooling step, the suspensions were immediately immersed in liquid nitrogen (LN), which were thawed after 2 days. Both U. lobata and H. musiformis survived maximally in 10% DMSO, whereas 10% glycerol was found most suitable for G. corticata. A slow cooling temperature of ?40?C and thawing temperature of 40?C were found most suitable irrespective of the species. The equilibration time of 60 min was found most suitable for G. corticata, while 45 min was sufficient for both H. musiformi and U. lobata. Cryopreserved vegetative thalli were then successfully regenerated, though the survival was considerably reduced up to a period of 28 days after which it was stabilized.     

Inter Annual and Seasonal Dynamics in Lipidic Signatures of Sardinella longiceps

ABSTRACT

Seasonal variations (premonsoon, monsoon, and postmonsoon) of the lipid, fatty acid, and total cholesterol profile in edible tissues of Sardinella longiceps collected from the southwest and southeast coasts of India over 4 yr (2008–2011) were studied. The correlation between the fatty acid composition with chlorophyll-a concentration, sea surface temperature, total phytoplankton density, diatom concentration, and fatty acid profiles of pooled stomach microalgal content were also evaluated. Significant correlation was observed between oil sardine and pooled stomach microalgal content polyunsaturated fatty acids along with chlorophyll-a concentration, especially during the monsoon at the southwest coast and monsoon and postmonsoon at the southeast coast of the Indian subcontinent. Similarly, the health indices such as atherogenic index, thrombogenicity index, total cholesterol, and hypocholesterolemic/hypercholesterolemic ratio of oil sardine were found to be ideal, which contributed toward its parameters to be qualified as an ideal health food.     

INLAND AQUACULTURE IN INDIA: PAST TREND,PRESENT STATUS AND FUTURE PROSPECTS

ABSTRACT

In India, inland aquaculture has emerged as a fast-growing enterprise and a viable alternative to the declining capture fisheries. The present paper is an attempt to assess Indian inland aquaculture with respect to its resource base, output trends, systems and activities, yield gaps, adoption and impact on aquaculturists, economics, returns to inputs, investment needs, and future prospects. The paper is largely based on existing literature and observations made as part of an ICAR-WorldFish demand supply project. Indian aquaculture is primarily limited to inland sector and carp-oriented; for that reason, this activity received special attention. Freshwater aquaculture observed tremendous growth in the past 15 years, but immense scope still exists for horizontal expansion and increases in productivity (vertical expansion). This is evidenced by the fact that the average farm fish yield is only one-third of that achieved in farm trials. The difference was mainly due to much higher input use in on-farm trials. Most of the aquaculturists were practicing extensive aquaculture, but aquaculturists with semi-intensive operations benefited most from adoption of technology. The benefit:cost ratios for different systems of aquaculture varied between 1.22 to 1.86. The return to capital was much higher than the return to labor, due to the low labor input. The semi-intensive aquaculture system would receive the greatest return from projected macrolevel investments, followed by extensive and intensive systems. Dedicated efforts are needed to meet the demand for quality fish seed and feed in order to achieve the desired 45% increase in area and greater than 50% increase in productivity. Based on the observations, activities designed to foster inland aquacultural development in India are recommended.     

Patterns of release of the secondary conidia of Claviceps africana, the sorghum ergot pathogen in Australia

Trials were conducted in southern Queensland, Australia between March and May 2003, 2004 and 2005 to study patterns of hourly and daily release of the secondary conidia of Claviceps africana and their relationships with weather parameters. Conidia were trapped for at least one hour on most (> 90%) days in 2003 and 2004, but only on 55% of days in 2005. Both the highest daily concentration of conidia, and the highest number of hours per day when conidia were trapped, were recorded 1–3 days after rainfall events. Although the pattern of conidial release was different every day, the highest hourly conidial concentrations occurred between 10·00 hours and 17·00 hours on 73% of all days in the three trials. Hours when conidia were trapped were characterized by higher median values of temperature, windspeed and vapour pressure deficit, lower relative humidity, and leaf wetness values of 0%, than hours when no conidia were recorded. The results indicate that fungicides need to be applied to the highly ergot-susceptible male sterile (A-) lines of sorghum in hybrid seed production blocks and breeders' nurseries as soon as possible after rainfall events to minimize ergot severity.     

Antitumor and Antimicrobial Activity of Some Cyclic Tetrapeptides and Tripeptides Derived from Marine Bacteria

Marine derived cyclo(Gly-l-Ser-l-Pro-l-Glu) was selected as a lead to evaluate antitumor-antibiotic activity. Histidine was chosen to replace the serine residue to form cyclo(Gly-l-His-l-Pro-l-Glu). Cyclic tetrapeptides (CtetPs) were then synthesized using a solution phase method, and subjected to antitumor and antibiotic assays. The benzyl group protected CtetPs derivatives, showed better activity against antibiotic-resistant Staphylococcus aureus in the range of 60–120 μM. Benzyl group protected CtetPs 3 and 4, exhibited antitumor activity against several cell lines at a concentration of 80–108 μM. However, shortening the size of the ring to the cyclic tripeptide (CtriP) scaffold, cyclo(Gly-l-Ser-l-Pro), cyclo(Ser-l-Pro-l-Glu) and their analogues showed no antibiotic or antitumor activity. This phenomenon can be explained from their backbone structures.