Identification of a major blast resistance gene in the rice cultivar 'Tetep'

Analysis of near‐isogenic lines (NILs) indicated the presence of a novel resistance gene in the indica rice cultivar ‘Tetep’ which was highly resistant to the rice blast fungus Magnaporthe grisea.‘Tetep’ was crossed to the widely used susceptible cultivar ‘CO39’ to generate the mapping population. A Mendelian segregation ratio of 3 : 1 for resistant to susceptible F₂ plants further confirmed the presence of a major dominant locus, in ‘Tetep’, conferring resistance to the blast fungal isolate B157, corresponding to the international race IC9. Simple sequence length polymorphism (SSLP) was used for molecular genetic analysis. The analysis revealed that the SSLP marker RM 246 was linked to a novel blast resistance gene designated Pi‐tp(t) in ‘Tetep’.     

Biology and seasonal abundance of the two-spotted spider mite, Tetranychus urticae, on orchids and rose

Biology of the two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) was studied on five orchids and one rose species under laboratory conditions. The duration of developmental stages of this mite was the shortest on rose (7.17 ± 0.20 days) followed by Cymbidium (10.49 ± 1.50 days), Oncidium (11.60 ± 1.32 days), Dendrobium (12.67 ± 0.21 days), Phalaenopsis (14.47 ± 1.21 days) and Coelogyne (17.10 ± 1.29 days). The number of eggs/female laid was maximum on rose, whereas the minimum was on Phalaenopsis under the most suitable temperature (26 ± 2°C) and relative humidity (65 ± 5%) conditions. The five orchid farms (three conventionally sprayed and two unsprayed) in the northeastern region of India were surveyed during 2009 and 2010 for mite incidence. Twenty-three species and 11 hybrids of orchids were encountered as the most preferred host, 12 species as moderately preferred, and 28 species and one hybrid were found to be the least preferred orchid host for T. urticae. The mite’s incidence was recorded on orchids all year round, indicative of overlapping generations; however, two distinct population peaks were recorded during April and May. Subsequently its population declined at the start of the rainy season and remained at extremely low levels in the winter. Maximum and minimum temperatures had a significant positive correlation with mite incidence; daylight had a non-significant positive correlation; and rainfall and relative humidity had non-significant negative correlations with mite incidence. The results are discussed in relation to the most susceptible stage on orchids and suitable management practices for the two-spotted spider mite in India.     

Putrescine and carnauba wax pretreatments alleviate chilling injury,enhance shelf life and preserve pomegranate fruit quality during cold storage

Keeping in mind to reduce chilling injury and retain quality; pomegranate (Punica granatum L., cv. Mridula) fruits were treated with putrescine, carnauba wax and putrescine + carnauba wax prior to cold storage at 2 °C. Before analyzing physical, physiological and biochemical parameters fruits were subjected to post cold storage exposure at 20 °C for 3 days. Untreated fruits developed rapidly chilling injury, with main symptoms being brown discolouration of the skin, surface pitting, weight and firmness loss during storage. All these undesirable changes were significantly delayed by putrescine + carnauba wax application. Respiration and ethylene evolution rate were also brought down by combined application of putrescine and carnauba wax treatment. The superiority of combine treatment over other applications seems arises due to additive benefit of antisenescence and barrier properties of putrescine and carnauba wax, respectively.     

Contamination of Soil and Plants with Potentially Toxic Elements Irrigated with Mixed Industrial Effluent and its Impact on the Environment

For productive utilisation of effluent–contaminated agricultural land, mobilisation and statistical analysis of potentially toxic elements in soil and plants of fields irrigated with mixedindustrial effluent have been undertaken. Total Fe,Mn, Zn, Cu, Pb, Ni and Cr have been estimated in soiland plant species of contaminated and noncontaminatedsites. 18 plants species and 18 root adjacent soilsamples from contaminated Kalipur area and 11 plantsspecies and 11 root adjacent soil samples fromuncontaminated Madhabpur area comprising majorcrops, vegetables and weeds have been included in thestudy. It is revealed that Hibiscusesculentus, Lycopersicon esculentum and Luffa acutangula growing in effluent–contaminated field show mobilisation ratio <0.5 for most of the PTE (Potentially Toxic Elements) likeCu, Pb, Ni, Cr and Cd and normal morphology.Surprisingly, weeds in particular, show highmobilization ratio >0.5 and simultaneously exhibithealthy gigantic morphology at the early floweringstage. Coriandrum sativum, Raphhanussativus, Solanum melongena, Spinaceaoleracea, Oryza sativum, Brassica oleraceashowed mobilization ratio >0.5 butmaintained normal growth. Based on mobilization ratioand external morphology, we suggest the cultivation ofplants H. esculentus, L. acutangula, L. esculentum in land irrigated with industrial effluent. The highest andsecond highest enrichment factor (EF_pp)was found for Cd and Pb, respectively. Pearson'scorrelation coefficient indicated that the metal levelin soil is not the main factor governing metaluptake. This study will help in selecting plantspecies for cultivation in contaminated fields.     

Nile tilapia (Oreochromis niloticus) seed production in irrigated rice-fields in Northwest Bangladesh—an approach appropriate for poorer farmers?

Participatory research was conducted with poorer farmers in two communities, Girai (G) and Bahagili (B) in NW Bangladesh to assess the production of Nile tilapia seed in irrigated spring rice-fields. All the selected households (G = 15; B = 4) had previous experience producing common carp (Cyprinus carpio) in the rice-fields allocated a separate plot in which a deeper area had been excavated for this trial. Mature GIFT strain Nile tilapia (12 female and 6 male; 121 ± 34 g and 158 ± 54 g size, respectively) were supplied to each household irrespective of the size of their trial plot (mean < 0.15 ha). The trial started in the spring rice season (boro) in February and ended at the end of main season (amon) in December 1999. Management practices, production and sales of fish were monitored weekly.The majority of farmers succeeded in producing fingerlings in their plots; 11% failed totally but around 70% produced more than 2000 fingerlings from a single plot. Production during boro and fallow period was much higher (> 90% total) than during the subsequent amon crop (< 10% total). Total production was highly variable among households but not different between the two study areas (G = 4092 ± 3277; B = 3730 ± 4232 fingerlings household^− 1). Daily production of fingerlings per unit area was relatively low (< 1 fish m^− 2 day^− 1) but efficiency of production was high, averaging 17.3 fingerlings. kg^− 1 female day^− 1. Mean individual harvest weight was 21 g.Most fingerlings were sold (43%) and/or stocked for further culture in their own grow-out system (39%), but some were used directly for household consumption (17%).     

Effect of inland water salinity on growth,feed conversion efficiency and intestinal enzyme activity in growing grey mullet, <Emphasis Type="Italic">Mugil cephalus</Emphasis> (Linn.): Field and laboratory studies

Two experiments were conducted to investigate the effect of inland water salinity on growth performance, feed conversion efficiency and intestinal enzyme activity in grey mullet. In experiment I, a 90 day monoculture of grey mullet at different salinity levels (0, 10, 15, 20 and 25%) was carried out. The fingerlings were stocked at 5000 per hectare and fed on a supplementary diet at 5% BW d^–1. This Study revealed that fish growth mean body weight (90.5 ± 4.5 g) and mean length (21.6 ± 0.4 cm), SGR (4.70%) and growth per day (0.99 g d^–1) were significantly (p < 0.05) enhanced in fish maintained at 10% salinity in comparison with other treatments. Nutrient levels, phytoplankton population, NPP and chlorophyll a all decreased with an increase in salinity (>10%). In addition, zooplankton populations increased with an increase in the salinity level. Most of the other hydrochemical characteristics remained at optimal levels in all other treatments. Fish weight gain showed a significant positive correlation with productivity indicating parameters viz. alkalinity (r = 0.53), turbidity (r = 0.62), NPP (r = 0.75) and chlorophyll a (r = 0.46), clearly revealing that fish growth is also related to the trophic status of the ponds. In the second experiment (Experiment II), mullet fry were exposed to five different salinity levels (10, 15, 20, 25 and 30%) and maintained for 70 days in the laboratory. Significantly (p < 0.05) high growth, (SGR and per cent increase in body weight), feed conversion efficiency and intestinal enzyme activity were observed in the group maintained at 10 salinity in comparison with other groups maintained at similar salinity levels. Carcass composition, musc1e and liver glycogen levels were also significantly (p < 0.05) affected by salinity changes.     

Empirical modelling of tensile strength of woven fabrics

Aesthetic properties of fabrics have been considered as the most important fabric attribute for years. However, recently there has been a paradigm shift in the domain of textile material applications and consequently more emphasis is now being given on the mechanical and functional properties of fabrics rather than its aesthetic appeal. Moreover, in certain woven fabrics used for technical applications, strength is a decisive quality parameter. In this work, tensile strength of plain woven fabrics has been predicted by using two empirical modelling methods namely artificial neural network (ANN) and linear regression. Warp yarn strength, warp yarn elongation, ends per inch (EPI), picks per inch (PPI) and weft count (Ne) were used as input parameters. Both the models were able to predict the fabric strength with reasonably good precision although ANN model demonstrated higher prediction accuracy and generalization ability than the regression model. The warp yarn strength and EPI were found to be the two most significant factors influencing fabric strength in warp direction.     

Three-week summer period prevalence of Clostridium difficile in farm animals in a temperate region of the United States (Ohio)

The cross-sectional (period) prevalence of Clostridium difficile in 875 farm animals from 29 commercial operations during the summer of 2008 in Ohio, USA was quantified. Compared to an external referent population of intensively managed race horses (12.7%), intensively managed commercially mature food animals (poultry, cattle, swine; < 0.6%) were infrequent shedders of C. difficile (P < 0.00001) during the warmest weeks of 2008.     

Effect of varying dietary protein levels on growth and production of Chanos chanos (Forsskal) in inland saline groundwater: laboratory and field studies

Two experiments were conducted to investigate the effects of varying dietary protein (35–45%) and energy levels (17.34–19.44 kJ g⁻¹) on the growth performance of milkfish (Chanos chanos) maintained under laboratory (experiment 1) and field conditions (Experiment 2) in inland saline groundwater. The results of experiment 1 (initial weight of fish: 0.25 g) revealed that, irrespective of the protein source (fish meal or processed full fat soybean), fish fed a diet containing 40% protein showed significantly (p<0.05) higher growth in terms of live weight gain and specific growth rate, low feed conversion ratio [1.71 (fish meal) and 1.58 (soybean)], high nutrient retention (gross protein retention: 28.59 and 31.05%; gross energy retention: 24.23 and 26.04%), apparent protein digestibility (81.74 and 85.91%) and digestive enzyme activity (specific protease and amylase). An observation on the postprandial excretion of metabolites (N–NH₄ and o–PO₄) indicated significantly (p<0.05) low levels of these metabolites in aquaria where the fish were fed 40% dietary protein irrespective of the protein source. The results of experiment 2 also indicate (initial weight of fish: 4.43 g) a significantly (p<0.05) higher growth performance (weight gain, biomass, specific growth rate, growth day⁻¹ and fish production) in ponds where the fish were fed 40% dietary protein. Irrespective of the experimental conditions (laboratory/field), feeding the fish higher dietary protein levels (beyond 40%) not only repressed growth performance but also affected proximate composition by lowering protein accumulation and energy assimilation. An investigation on the effects of feeds on water quality parameters revealed that values for total alkalinity, NH₄–N, NO₃–N, turbidity, total dissolved solids and parameters indicative of productivity (chlorophyll a, net primary productivity and plankton population) increased significantly (p<0.05) from treatments 1–3 (35–40% protein) and declined thereafter, in treatment 4 (42% dietary protein), indicating that water quality characteristics correlated well with fish growth. The results suggest that in order to obtain a high-yield in milkfish culture system the fish should be fed supplementary diets containing appropriate (40%) protein levels, especially when the stocking rates are high.