An optimised protocol for molecular identification of Eimeria from chickens

Molecular approaches supporting identification of Eimeria parasites infecting chickens have been available for more than 20 years, although they have largely failed to replace traditional measures such as microscopy and pathology. Limitations of microscopy-led diagnostics, including a requirement for specialist parasitological expertise and low sample throughput, are yet to be outweighed by the difficulties associated with accessing genomic DNA from environmental Eimeria samples. A key step towards the use of Eimeria species-specific PCR as a sensitive and reproducible discriminatory tool for use in the field is the production of a standardised protocol that includes sample collection and DNA template preparation, as well as primer selection from the numerous PCR assays now published. Such a protocol will facilitate development of valuable epidemiological datasets which may be easily compared between studies and laboratories. The outcome of an optimisation process undertaken in laboratories in India and the UK is described here, identifying four steps. First, samples were collected into a 2% (w/v) potassium dichromate solution. Second, oocysts were enriched by flotation in saturated saline. Third, genomic DNA was extracted using a QIAamp DNA Stool mini kit protocol including a mechanical homogenisation step. Finally, nested PCR was carried out using previously published primers targeting the internal transcribed spacer region 1 (ITS-1). Alternative methods tested included sample processing in the presence of faecal material, DNA extraction using a traditional phenol/chloroform protocol, the use of SCAR multiplex PCR (one tube and two tube versions) and speciation using the morphometric tool COCCIMORPH for the first time with field samples.     

Ecological monitoring for ascertaining the bio-safety of liver lipids from some Indian marine puffer fishes

ABSTRACT:   Ecological investigations were carried out on Indian marine puffers, Chelonodon patoca, Sphaeroides oblongus, Lagocephalus lunaris and Lagocephalus inermis , the four major species available in the coastal waters of the Bay of Bengal, India. The seasonal intraspecific and interspecific abundance and average daily landings were noted. The high hepatosomatic index and low lipid ratio of muscle to liver indicated accumulation of lipid in the liver. The lipid content was at its maximum during the monsoon (July–October) in all the species as was observed from the study of the seasonal variation of liver lipids. The puffers are mainly bottom feeders and the molluscs Umbonium vesterium and Donax incarnatus are the major prey group, constituting 56.0–87.5% of their food content. The liver and ovary had the maximum toxicity in monsoon during their spawning season. The liver oils so far tested from these fishes had no toxicity and the study reveals that the ecologic information will be helpful in monitoring the quality for the safe isolation of polyunsaturated fatty acid – enriched oil from these non-conventional sources.     

Development of a radioimmunoassay procedure for aflatoxin B1 measurement

A radioimmunoassaay (RIA) procedure to measure aflatoxin B(1) (AfB(1)) in agricultural commodities was developed. AfB(1) oxime derivative was synthesized, characterized, and used for preparation of (125)I-labeled AfB(1). Antiaflatoxin B(1) serum was raised in-house using AfB(1)-bovine serum albumin conjugate as immunogen. The assay system was optimized in the range of 0.2-5 ng/mL, using a liquid phase (PEG) as well as a solid phase (coated polystyrene beads) separation system. Inter-assay and intra-assay variations, recovery, and parallelism studies validated the assay. AfB(1) analysis was carried out in nearly 130 samples of different agricultural commodities. The correlation coefficient was determined using commercial ELISA and in-house-developed RIA methods.     

Evidence for Glacial Control of Rapid Sea Level Changes in the Early Cretaceous

Lower Cretaceous bulk carbonate from deep sea sediments records sudden inputs of strontium resulting from the exposure of continental shelves. Strontium data from an interval spanning 7 million years in the Berriasian-Valanginian imply that global sea level fluctuated about 50 meters over time scales of 200,000 to 500,000 years, which is in agreement with the Exxon sea level curve. Oxygen isotope measurements indicate that the growth of continental ice sheets caused these rapid sea level changes. If glaciation caused all the rapid sea level changes in the Cretaceous that are indicated by the Exxon curve, then an Antarctic ice sheet may have existed despite overall climatic warmth.     

Early life recorded in archean pillow lavas

Pillow lava rims from the Mesoarchean Barberton Greenstone Belt in South Africa contain micrometer-scale mineralized tubes that provide evidence of submarine microbial activity during the early history of Earth. The tubes formed during microbial etching of glass along fractures, as seen in pillow lavas from recent oceanic crust. The margins of the tubes contain organic carbon, and many of the pillow rims exhibit isotopically light bulk-rock carbonate delta13C values, supporting their biogenic origin. Overlapping metamorphic and magmatic dates from the pillow lavas suggest that microbial life colonized these subaqueous volcanic rocks soon after their eruption almost 3.5 billion years ago.     

Environmental fate of trifloxystrobin in soils of different geographical origins and photolytic degradation in water

In vitro biodegradation of trifloxystrobin (TFS) under darkness could best be explained by two-compartment first + first-order rate kinetics with half-lives ranging between 1.8 and 2.3 days. Hydrolysis was found to be the major pathway of degradation resulting in the formation of the acid metabolite, TFS-acid, with an EE conformation. The adsorption rate kinetics of both TFS and TFS-acid followed linear and Freundlich isotherms. The extent of adsorption was directly correlated with organic matter and clay contents, whereas desorption had a negative correlation. The high partition coefficients (KD) indicate strong adsorption of TFS on all of the test soils without any appreciable risk of groundwater contamination. In case of the TFS-acid, however, the adsorption was weaker; hence, if its further degradation is slow, it may contaminate lower soil horizons under worst case conditions. TFS did not cause any adverse effect on the soil microbial population. TFS was susceptible to aquatic photolysis in summer with an environmental half-life of 0.7-1.3 days irrespective of the latitudes.     

Comparison of organic and conventional farming for onion yield,biochemical quality,soil organic carbon,and microbial population

In an ongoing field experiment, organic and conventional farming (control) were compared for onion bulb yield, biochemical quality, soil organic carbon (SOC), and microbial activity after the sixth cropping cycle. The treatments used for organic production were farmyard manure (FYM, 20,000 kg ha^?1), poultry manure (PM, 10,000 kg ha^?1), vermicompost (VC, 10,000 kg ha^?1), neem cake (NC, 5000 kg ha^?1), and a combination of FYM (5000 kg ha^?1), PM (2500 kg ha^?1), VC (2500 kg ha^?1), and NC (1250 kg ha^?1); all treatments were compared with the control. Organic treatments produced 24.6–43.6% lower yield consistently for 6 years than the control treatment. No significant difference was observed between PM, FYM, and VC treatments for the bulb yield. Bulb analysis during the sixth year indicated that plants that received FYM, PM, or VC had higher levels of total phenol, total flavonoid, ascorbic acid, and quercetin-3-glucoside than the control plants. All the five organically treated sets had significantly higher values of SOC, microbial population, fungal-to-bacterial ratio, and dehydrogenase activity than the control and the initial values in each treated set. The results indicate that FYM, PM, or VC application enhances biochemical quality and organic farming is more sustainable than conventional farming.     

Herbicide ready-mixes effects on weed control efficacy,non-target and residual toxicities,productivity and profitability in sugarcane–green gram cropping system

Weeds pose a major challenge at the initial stages of sugarcane and when uncontrolled cause high yield losses. This study was undertaken to define a better and cost-effective weed management strategy. We compared ametryn + trifloxysulfuron-sodium (hereafter referred to as trifloxysulfuron) ready-mixes with single applications of trifloxysulfuron, atrazine and 2,4-D for efficacy, non-target and residual toxicities, yield and profitability in a sugarcane–green gram rotation. Results showed that a density of 100 weeds m^?2 could reduce sugarcane yield by 18.4 t ha^?1. The ready-mix ametryn + trifloxysulfuron (1097.3 + 27.8) g a.i. ha^?1 applied 15 days after planting (DAP) caused reductions in weed density by 88.2%, 90.9%, and 90.3%, and weed biomass by 68.0%, 53.8%, and 56.2% compared to unweeded control at 30, 60, and 90 DAP, respectively. Consequently, the sugarcane yield, system productivity, and net returns were increased by 92.1%, 43.5%, and 1515%, respectively due to this ready-mix. It increased system productivity by 23%, 17.2%, and 22.7% compared to trifloxysulfuron, atrazine, and 2,4-D treatments, respectively. This ready-mix may be recommended in sugarcane. This would reduce weed seed bank and herbicide application cost by 50%, and prevent/delay weed shift and resistance.