Enrobed Snack Product from Devis’s Anchovy (Stolephorus commersonnii) and its Quality Evaluation during Frozen Storage

Enrobing of fish improves physical as well as consumer acceptance of low value fish. The present work was undertaken to utilize a low value fish with its bones by enrobing with cereal flour based coating. Three combinations of batters were prepared, and the fish was coated and fried; based on the sensory quality, 1:2 batter to water ratio was selected for product preparation. To determine the storage life, frozen par-fried samples were prepared and stored at ?18°C. Quality parameters such as pH, total volatile basic nitrogen, free fatty acids, peroxide value, thiobarbituric acid reactive substances, color, and sensory attributes were evaluated on a monthly basis. It was observed from chemical parameters and sensory scores of the product that the par-fried form can be stored for up to 5 months. This technology will provide a better opportunity for employment of coastal women.     

An enzyme-linked immunosorbent assay (ELISA) for detection of Marek's disease virus-specific antibodies and its application in an experimental vaccine trial

An enzyme-linked immunosorbent assay (ELISA) for the detection of Marek's disease virus (MDV)-specific antibodies was developed. Chicken embryo cells (CEC) or chicken kidney cells (CKC) were infected with MDV vaccine strain CVI988/Rispens, and infected-cell lysates were prepared at day 5 post-infection by freeze-thawing. Uninfected-cell lysates served as negative controls. Sera were used at a 1 : 100 dilution and were added in parallel to wells containing the infected and uninfected cell lysates. The optical densities at 492 nm (OD(492 nm)) were measured after detection of bound chicken antibodies with anti-chicken IgG peroxidase conjugate and colour reactions using o-phenylenediamine (OPD) as a substrate. The best results concerning the signal-to-noise ratio were obtained by using CKC cells rather than CEC for antigen preparation. The OD(492 nm) of plasma or serum samples with infected CKC was <0.02 when samples of unvaccinated and unchallenged maternal antibody-negative white leghorn chickens were tested. Sera and plasma samples of positive control birds exhibited OD(492 nm) of <0.01 when tested with uninfected CKC. The assay was used to monitor a trial that compared experimental BAC DNA vaccines and a commercial vaccine. Sustained seroconversion and antibody titers that were constantly rising until day 84 after vaccination (71 days after challenge) was observed only when chickens did not develop Marek's disease. In contrast, chickens developing the disease mounted marginal and short-lived antibody titers only. We conclude that the developed ELISA may be a valuable tool for the evaluation of the efficacy of MDV vaccination under experimental but possibly also under field conditions.     

Extended summaries pesticides group symposium natural products as a source for new agricultural chemicals

The following are extended abstracts of six of the papers presented at the above meeting and, as so presented, they are entirely the responsibility of the authors and do not reflect the views of the Editorial Board of Pesticide Science.     

Interactions among cutting frequency, reserve carbohydrates, and post-cutting biomass production in Gliricidia sepium and Leucaena leucocephala

The ability of trees and shrubs to coppice vigorously after being cut or pruned is of great importance in the management of agroforestry systems. In a study conducted in the seasonally dry climate of Ibadan, Nigeria, frequent cutting progressively decreased concentrations of starch and total reserve carbohydrates in Gliricidia sepium (Jacq.) Walp. and Leucaena leucocephala (Lam.) De Wit. In frequently cut trees, starch was severely reduced in the stumps of both species. In contrast, soluble sugar concentrations in roots and stems of both species were consistently maintained at or above the levels in uncut control trees, suggesting that sugar levels were maintained through the hydrolysis of starch reserves. No starch replenishment occurred during the six weeks after cutting. In trees that were cut and then allowed to grow undisturbed during the wet season, replenishment of stem starch began within three months after cutting. Shoot regrowth after cutting decreased starch levels first in stems and, only after additional cuts, in roots. Dry-season cuts had little effect on reserve carbohydrates in G. sepium but quickly reduced stem starch in L. leucocephala. Frequent cutting decreased dry matter production, and this decrease was correlated with reduced levels of reserve carbohydrates.This revised version was published online in November 2005 with corrections to the Cover Date.     

Analysis of genetic diversity and phylogeny in Saccharum and related genera using RAPD markers

Molecular diversity in Saccharum complex was studied using 195 RAPD markers generated by 12 random primers. Among the Saccharum species, S. officinarum showed a low level of genetic diversity while S. sinense was found to be more diverse. Six taxonomical groups were clearly resolved in the cluster analysis. S. officinarum, S. robustum, S. spontaneum and Erianthus spp. formed discrete groups. S. barberi and S. sinense formed a single cluster, so also Narenga and Sclerostachya. S. officinarum was found to be closer to S. robustum and distant from S. spontaneum. Among the related genera, Sclerostachya was closer to Saccharum while Erianthus was found to be highly divergent from all the Saccharum species. Six of the primers used generated RAPD fragments unique to Erianthus. It is suggested that the Erianthus spp. can contribute substantially towards sugarcane varietal improvement in view of its greater divergence with Saccharum.     

Plant‐available N:P alters root litter N recycling in a Mediterranean tree–grass ecosystem

Background: Nitrogen deposition can cause an ecosystem‐level shift in available N (nitrogen) to P (phosphorus) availability. However, most plant N nutrition is from edaphic sources rather than deposition and in seasonally dry grassland systems, root litter is the predominant nutrient source. Aims: We were interested how litter turnover and altered nutrient recycling from dead biomass can compensate for these shifts in ecosystem stoichiometry. Methods: We studied a Mediterranean savanna amended with N or NP treatments three years prior. We measured root and plant‐available soil N:P stoichiometry in two micro‐habitats: open pasture and beneath oak canopies. ¹⁵N‐labelled root litter incubated in topsoils without litterbags was used to trace uptake of litter N by herbaceous strata roots. Results: Since fertilization, NP added sites have become relatively P enriched, resulting in lower N:P ratios in living roots than either when N was added alone or control sites. Total litter‐derived ¹⁵N uptake by roots was proportional to root ingrowth response but higher in the NP than N treatment, indicating a higher N demand when N and P were added together. We observed more ¹⁵N uptake by plants under tree canopies, indicating a tighter nutrient recycling loop in these micro‐habitats in contrast to treatment level ‘fertility' trends. Conclusions: Root stoichiometry responded to manipulated soil nutrient availability and N uptake was altered as plants attempted to compensate for nutrient availability imbalances, indicating that these ecosystem perturbations have long term effects on nutrient cycling which can propagate to whole system function. This was also related to functional community‐level adaptions between micro‐habitats with under canopy communities more able to take advantage of the litter nutrient source.