Molecular cloning,sequence analysis and tissue expression of translationally controlled tumour protein from the WSSV‐infected Indian shrimp Penaeus indicus

The gene coding for translationally controlled tumour protein (TCTP) was polymerase chain reaction amplified from haemocyte cDNA of Indian shrimp, Penaeus indicus, and sequenced. The N‐terminal region, a conserved one among all the TCTPs, was shown to have one substitution at position 37, in the Indian isolate. Besides this, there were two substitutions in the C‐terminal region (135, 149), exclusive to the Indian isolate. Phylogenetic analysis suggested a close relatedness of TCTP from P. indicus to Fenneropenaeus chinensis compared with other isolates. Translationally controlled tumour protein gene expression was found to be elevated in the haemocytes of WSSV‐infected shrimps compared with the uninfected ones. However, tissues from the infected shrimps did not exhibit any detectable levels of TCTP expression.     

Influence of two insecticides, chlorpyrifos and quinalphos, on arginine ammonification and mineralizable nitrogen in two tropical soil types

Effects of seed treatments with chlorpyrifos [5 g of active ingredient (ai) kg(-1) of seed] and quinalphos (6.25 g of ai kg(-1) of seed) and standing crop treatments with chlorpyrifos (800 g of ai ha(-1)) and quinalphos (1000 g of ai ha(-1)) on arginine deamination and mineralizable nitrogen were monitored, in the sandy loam and loamy sand soils of two tropical semiarid fields, for three consecutive crop seasons. The arginine ammonification activity of rhizospheric microbes was inhibited after seed treatment with chlorpyrifos and quinalphos and their principal metabolites, 3,5,6-trichloro-2-pyridinol (TCP) and 3,5,6-trichloro-2-methoxypyridine (TMP) and 2-hydroxyquinoxaline and quinoxaline-2-thiol, respectively. Quinalphos produced transient inhibitions, whereas chlorpyrifos and its metabolites (TCP and TMP) exerted a greater inhibition in both loamy sand and sandy loam soils. Arginine ammonification by nonrhizospheric microbes was stimulated by standing crop treatments with both pesticides. In the loamy sand soil, the parent compounds stimulated rhizospheric N-mineralization, whereas the metabolites were inhibitory. However, nonrhizospheric N-mineralization was inhibited by both chlorpyrifos and quinalphos and stimulated by their metabolites. A higher magnitude of inhibition of arginine deamination in the loamy sand than in the sandy loam soil could be due to greater bioavailability of the pesticides in the former, resulting from lesser sorption of the pesticides due to alkalinity of the soil and its low content of clay and organic carbon. Although both pesticides affected mineralizable nitrogen, seed treatment with quinalphos and standing crop treatment with quinalphos and chlorpyrifos produced the most significant effects. The recommended doses of the pesticides not only efficiently controlled whitegrubs, which increased pod yields, but also left no residues in harvested kernels. They also caused no long-term inhibition of ammonification, which could have been of significant concern during the short crop period in semiarid areas where nitrogen determines plant productivity.     

Cloning and analysis of the gene for a major surface antigen of Mycoplasma gallisepticum

Myplasma gallisepticum infects a wide variety of gallineaceous birds including chickens, turkeys, and pheasants. Infection occurs both horizontally and vertically. Thus, control of the spread of M. gallisepticum to noninfected flocks is difficult. Continual monitoring is necessary to identify infected flocks even under the most stringent infectious control practices. Monitoring, however, is usually performed by measuring hemagglutination activity (HA) in serum, an insensitive and variable test. Variability in the HA test arises differences in agglutination antigen, changes in antigenic profiles of the M. gallisepticum strain, and variability in reading the agglutination reaction. Enzyme-linked immunosorbent assays (ELISAs) are the preferred method of testing because of the ease in obtaining sera and the sensitivity and reproducibility of the assays, but the ELISA suffers from a lack of standardization in the test antigen. The ELISA test will be more easily accepted once the test antigen has been standardized. To this end, we have identified, cloned, and characterized the gene for an antigen that has potential as a species-specific antigen for M. gallisepticum The gene codes for a 75-kD protein, P75, that is recognized during natural infections. Recombinant P75 is not recognized in immunoblots by convalescent sera produced in chickens infected with Mycoplasma synoviae, Mycoplasma gallinarum, and Mycoplasma gallinaceum or in turkeys infected with Mycoplasma meleagridis.     

Toxicity of Neonicotinoid Pesticide Imidacloprid and Impediment of Ecosystem Services

In agro-ecosystems, pollinators perform a variety of ecological services. The ecological role of pollinators and their ecosystem services are critical to the health of many ecosystems. Pollination by birds and bees are recognized as an important ecosystem function maintaining the dynamics of agro-ecosystems. As agriculture covers a significant portion of the globe, it necessitates the evaluation of their ecosystem services. There are overwhelming evidence that pollinators are experiencing tremendous population decline. Global agricultural encroachment, agriculture intensification, changes in cropped pasture, urban development and extensive use of pesticides are the major threats to farmland birds. Despite ecological importance and global awareness, farmland birds and bees are often considered as species of low conservation value. The worldwide use of neonicotinoid insecticides has raised concern over the decline of pollinators in the farmlands globally. Neonicotinoids are neurotoxins, applied to variety of agricultural crops to control sucking and biting pests and are readily incorporated into plant cells, inclusive of pollen and nectar. Among neonicotinoids, imidacloprid is found to have startling effects, disrupting several ecosystem services, inhibiting pollination and threatening global food security. The study focuses on imidacloprid and its wider risk to the environment with effects on non-target pollinators especially birds and bees. Some of the effects on bees include disrupting social behavior, foraging and altered navigation and in birds reduced reproduction and offspring immunity. Though the scientific community is intently examining the potential effects of imidacloprid on pollinators, the research warrants further investigations with field-realistic concentrations and at relevant exposure levels. This would facilitate the functioning of pollinators and promote sustainable agriculture by reducing the impact of neonicotinoids. This review summarizes the potential lethal and sublethal effects of neonicotinoid pesticide imidacloprid on pollinators and other invertebrate groups and also helps us to better understand the extent of their toxicity.     

Metal nanotubule membranes with electrochemically switchable ion-transport selectivity

Membranes containing cylindrical metal nanotubules that span the complete thickness of the membrane are described. The inside radius of the nanotubules can be varied at will; nanotubule radii as small as 0.8 nanometer are reported. These membranes show selective ion transport analogous to that observed in ion-exchange polymers. Ion permselectivity occurs because excess charge density can be present on the inner walls of the metal tubules. The membranes reject ions with the same sign as the excess charge and transport ions of the opposite sign. Because the sign of the excess charge on the tubule can be changed potentiostatically, a metal nanotubule membrane can be either cation selective or anion selective, depending on the potential applied to the membrane.     

Collection and Characterisation of Malabar Tamarind [Garcinia cambogia (Gaertn.) Desr.]

A collaborative crop specific exploration and collection mission to collect the germplasm and to study the population size of male and female/hermaphrodite trees of Malabar tamarind [Garcinia cambogia (Gaertn.) Desr.] in the area of its diversity was undertaken during July 2002 in Kerala and Karnataka. A total of 56 accessions of Malabar tamarind were collected. Two collections of Malabar tamarind were found to be very specific because of the uncommon fruit colour, which is pinkish red. All the collected accessions are grown at National Bureau of Plant Genetic Resources (NBPGR) Regional Station, Thrissur for characterisation and conservation. Extensive range of variability was found in fruit colour, shape, size and nature of branching and canopy of trees. Characterisation of 13 fruit and five seed characters was done for 51 accessions. The variability was found to be maximum for nipple length (74.8%) and minimum for fruit girth (12.8%). Two promising accessions were identified based on mean fruit weight (161 g) in IC 354028 and mean rind thickness (15 mm) and mean rind weight (125 g) in IC 354019.     

Towards sustainable freshwater prawn aquaculture – lessons from shrimp farming, with special reference to India

The annual increase in farmed freshwater prawn production in the world during the decade ending 2001 has been estimated as 29% and that during 1999–2001 as 48%, the production in 2001 being about 300 000 mt (all Macrobrachium species). Between 1999 and 2003 the annual increase in farmed Macrobrachium rosenbergii production in India was about 80%, production reaching 30 450 mt in 2002–2003. This log phase of production followed the rise and fall of shrimp farming in the country. Several shrimp farming ventures collapsed in the 1990s, owing to degraded environment and diseases, abetted by lack of awareness and inadequacy of information on the culture systems and their interactions with other human endeavours. This shrimp farming experience has made the aquafarmer and other stakeholders aware that while aquaculture has a high potential in ensuring food and nutritional security and livelihood, besides profit to the farmer and socio‐economic benefits to local communities, it is likely to slip from sustainable development pathways if adequate understanding, improved management practices, governmental policies and plans for implementation and regulation to ensure sustainability are not in place. The lessons learned from shrimp farming can help in steering the development of sustainable freshwater prawn aquaculture in India and elsewhere.