Relative efficacy of organic manures on rice production in lateritic soil

Abstract. Field experiments were carried out to evaluate the relative efficacy of organic manures in improving the productivity and pest tolerance of rice growing in a lateritic soil. The effects of three commercial manures: processed city waste (PCW), vermicompost (VC) and oil cake pellets (OCP), were assessed in comparison to farmyard manure (FYM) and inorganic fertilizer all at the same total N applied. Of the organic manures tested, FYM produced the maximum straw and grain yields. Differences in yield among the organic manure treatments were mainly attributed to variation in the amounts of available N, P, K and micronutrients. Effect of manures on soil physical condition was not studied. The uptake of N, P and K by rice plants with FYM was significantly greater than all other commercial manures and inorganic fertilizer. The tolerance of rice plants to attack by pathogens and pests, measured in terms of grain yield was highest in the treatment with FYM. Among the commercial manures PCW showed the greatest promise and emerged as a potential alternative to FYM.     

Population dynamical consequences of climate change for a small temperate songbird

Predicting the effects of an expected climatic change requires estimates and modeling of stochastic factors as well as density-dependent effects in the population dynamics. In a population of a small songbird, the dipper (Cinclus cinclus), environmental stochasticity and density dependence both influenced the population growth rate. About half of the environmental variance was explained by variation in mean winter temperature. Including these results in a stochastic model shows that an expected change in climate will strongly affect the dynamics of the population, leading to a nonlinear increase in the carrying capacity and in the expected mean population size.     

Vitellogenesis with special emphasis on Indian fishes

Oocyte growth in most oviparous vertebrates including fish is due to the formation of yolk, and eggshell proteins (zona radiata proteins). Zonagenesis leads to the formation of zona radiata proteins in oocytes, which play an important role during oogenesis, whereas vitellogenesis leads to the formation of yolk in oocytes through a series of events during which the yolk precursor protein vitellogenin (Vg) is synthesized and secreted from liver into blood from where it is sequestered into the developing oocytes and thereafter proteolytically cleaved to form yolk proteins (YPs) and finally deposited in the ooplasm. Much research has been done in many fish species with respect to the number and nature of Vg and YPs and their probable functions during fish reproduction. Recent findings of multiplicity of Vg molecules in fishes reject the earlier view of a single-Vg model and have led scientists to explore the functions of individual Vg and their YP derivatives, lipovitellin, phosvitin, and β′-component. Two distinct types of Vg or Vg genes, containing or encoding the three YPs, have been detected in many teleosts. A third unusual, incomplete, phosvitin-poor Vg has been described recently in many fishes. In comparison to much of the information on vitellogenesis in many fishes very little is known for Indian fishes. In India research has been done in a few species such as the catfish, Heteropneustes fossilis and Clarias batrachus, the murrel, Channa punctatus and the Indian major carps, Labeo rohita and Cirrhinus mrigala. Immunological and biochemical analyses suggest the occurrence of multiple forms of Vg and their YP derivatives. The synthesis and incorporation of Vg are regulated by gonadotropin (GTH) and estradiol-17β (E₂). A differential role between estrone (E₁₎ and estriol (E₃) has been demonstrated for Vg synthesis. Enzyme-linked immunosorbent assays (ELISAs) for Vg have been developed to measure plasma Vg. Finally the different roles of Vg1 (HAI) and Vg2 (HAII) on vitellogenesis have been demonstrated. However, more research remains to be carried out in other fish species with respect to the number and nature of Vg and YPs and their genes in order to describe their reproductive functions.     

Effect of Selection for Days to Flower in X-ray Treated Population of Jute (Corchorus capsularis L.)

Dry seeds of an early variety of jute (Fanduk) were X-irradiated to study the effect of selection for days to flower. Variation was induced in days to flower as evident from the high values of genotypic variances and hen lability estimates in the Mi generation. Asymmetric-response was realized in the M4 generation following disruptive selection — response being more towards lateness than earliness. However, significant variances for days to flower were present among both early and late selections in M4 generation. While late lines were superior to the mother variety in plant height and fibre vie Id: pi ant, early lines were inferior to the mother variety in these-traits. Distribution of 15 late lines in fibre yield and plant height classes showed that S lines exceeded the mother variety in fibre yield, plant and 7 of them exceeded it in plant height. In general, gradual shift towards lateness was associated with gradual shift towards greater plant height and fibre yield. Two late lines were very promising and earlier in maturity than the recommended early varieties.     

Benzimidazole drugs and modulation of biotransformation enzymes

Benzimidazole drugs (e.g., anthelmintics albendazole, fenbendazole, oxfenbendazole, thiabendazole, mebendazole; inhibitors of proton pump omeprazole, lansoprasole, pantoprasole) represent substances used in both human and veterinary medicine; however, from the point of view of induction and inhibition of biotransformation enzymes, research has been carried out mainly due to the initiative of human pharmacologists. The purpose of the present review is to inform about inductive and inhibitive effects of benzimidazole drugs in man, animals and cell cultures. Pharmacological and toxicological consequences of modulation of biotransformation enzymes are discussed and the significance of studies in the field of modulation of biotransformation enzymes in food-producing animals is explained. Since the modulating effect of benzimidazoles strongly varies depending on structure of the individual substances, the particular attention is paid to structure-modulation relationships.     

An improved micropropagation protocol for the recalcitrant plant Capsicum – a study with ten cultivars of Capsicum spp. (C. annuum,C. chinense,and C. frutescens) collected from diverse geographical regions of India and Mexico

Capsicum spp. is a commercially important crop of the Solanaceae family, well-known for its multipurpose use as a vegetable, spice, medicinal and ornamental plants. The genus Capsicum is a recalcitrant species in terms of in vitro morphogenesis and plant regeneration. An efficient method was developed for multiple shoot regeneration in 10 cultivars of Capsicum collected from diverse geographical regions of India and Mexico. Seeds germinated in vitro on a half-strength Murashige and Skoog (MS) medium supplemented with 3.0 % sucrose. Nodes of the in vitro germinated seedlings were used as explant for micropropagation. The combination of the 6-benzylaminopurine, indole-3-acetic acid, and spermidine was found to be the best for multiple shoot induction. However, the optimum responcse varied accompanied by different cultivers with maximum 8.9 ± 0.52 (Capsi-10) to 15.3 ± 0.69 (Capsi-5) multiple shoot per explant. Depending on the cultivar, multiplied shoots were successfully rooted with maximum 18.4 ± 0.20 (highest for Capsi-9) to 36.8 ± 0.29 (highest for Capsi-5) roots per shoot on half-strength MS medium supplemented with 2.0 mg l^?1 indole-3-butyric acid, 1.0 mg l^?1 α-naphthalene acetic acid, and 1.5 mM spermidine. Finally, the micropropagated plantlets were acclimatized with 40.0–86.7 % survival rate, depending on different cultivars.     

Mouflon (Ovis musimon) dicrocoeliosis: effects of parasitosis on the activities of biotransformation enzymes and albendazole metabolism in liver

Parasitic infections can modify the host's ability to metabolize drugs and other xenobiotics by altering the biotransformation enzymes; these changes may have various pharmacological, toxicological or physiological consequences. In our study, several activities of liver biotransformation enzymes and in vitro metabolism of albendazole (ABZ) were tested and compared in non-infected mouflons (Ovis musimon) and in mouflons infected by lancet fluke (Dicrocoelium dendriticum). Subcellular fractions of liver homogenates were isolated from 5+5 mouflon rams (1-year-old) parasitologically negative or naturally infected by fluke. From the eight enzyme activities that were assayed, only two activities significantly differ in the case of Dicrocoelium-infected versus non-infected animals. In infected mouflons, a significant increase (53%) of thiobenzamide-S-oxidase (TBSO) activity, corresponding mainly to the activity of flavine monooxygenase (FMO), and significant decrease (60%) of glutathione-S-transferase (GST) activity was observed. In addition, dicrocoeliosis caused the enhancement of ABZ hepatic biotransformation. The velocity of the formation of (+)-ABZ sulfoxide and ABZ sulfone was significantly increased. However, the shifts in ABZ biotransformation were very mild that undesirable alterations in ABZ pharmacokinetic are not expected. From this point of view, the use of ABZ in the therapy of mouflon dicrocoeliosis in young animals can be recommended. The treatment of the same mouflons by other drugs that are mainly conjugated with glutathione, seems to be more problematic; hence, all consequences of documented reduced GST activity should be accounted.     

Fate of blue-green algae in the food web of flooded rice-field ecosystems

 As part of an integrated pest management project to study the role blue-green algae (BGA) may play in the food web of rice-field ecosystems, ¹⁴C-labelled filamentous and monocellular BGA were used as food for fish, zooplankton and benthic fauna in artificial rice fields in the form of three aquaria. ¹⁴C present in the organisms was then traced by liquid scintillation to follow the manner in which the labelled BGA were consumed by different organisms. In this study the grazing rate of fish (mud carp) was compared to that of benthic organisms and zooplankton. It was found that fish consumed the BGA at the fastest rates and in the largest amounts, followed by the benthic species and zooplankton. It was also found that filamentous BGA were consumed in higher amounts than monocellular BGA. The importance of grazing in nutrient recycling is emphasized. Received: 22 December 1997     

A Voice-of-Consumer Approach in Development of New Seafood Product Concepts

This article describes a consumer-based approach for development of new seafood product concepts among young adults in Norway and Iceland. The study aim was to gain insight into how young adults determine their acceptance of seafood and make potential product choices. Additional insights measured were confidence in seafood preparation and consumption choices when exposed to specific new seafood concepts. Based on consumer-reported values, three seafood product concepts were evaluated by 354 consumers in a web-based, conjoint experiment in Norway and Iceland. Consumers' evaluations showed a number of consumer preferences for specific seafood product concepts partly associated with and partly conflicting with their original values. Understanding consumer attitudes can help to explain these results. The results of this study will be used as a guide for the next step in developing seafood product concepts.     

The importance of egg size and egg energy density for early size patterns and performance of Arctic charr Salvelinus alpinus

The primary target of selection in most breeding programmes in aquaculture is to promote rapid growth while delaying maturation. In most cases, little is known about how such selection programmes may affect maternal provisioning of offspring and early development. Under favourable and predictable condition, which is typically the case in fish farming, females generally produce more but smaller eggs than wild females. By using a continuous range of egg size originating from females of a fourth generation of Icelandic domesticated Arctic charr Salvelinus alpinus (Linnaeus, 1758), we assessed the relative importance of maternal effects and individual egg size for energy density of individual egg and several offspring traits from fertilization until 138 days post fertilization (dpf). We found that egg size and related energy density varied more among than within females. Although egg size was not correlated with energy density (at 1 dpf) or survival (at hatching and 138 dpf), it was positively correlated with most offspring traits throughout ontogeny. We further did not find any temporal variation in the correlation with the offspring traits during ontogeny. Within clutch variation in growth, yolk sac volume and hatching time were under the influence of direct female effects (maternal or genetic effects). These results show how egg size relates to individual performance in Arctic charr and constitute a baseline for understanding how domestication may alter offspring phenotypes early in life. These findings are discussed with regard to their consequences for aquaculture of Arctic charr and salmonids in general.