Methylene Blue Adsorption onto Water Hyacinth: Batch and Column Study

The adsorption of methylene blue cationic dye by water hyacinth root was studied in a batch system. The experimental data isotherms were analyzed using the Langmuir and Freundlich equations. The monolayer adsorption capacity for methylene blue dye was found as 0.187?kg?kg^?1. Three kinetic models (the pseudo-first order, the pseudo-second order, and the unified approach) were used to calculate the adsorption rate constants. The kinetic data along with equilibrium constants (maximum monolayer capacity and Langmuir constant) fitted well with unified approach model for different initial concentrations, and the rate constants were determined. Laboratory column experiments were conducted to evaluate the performance of water hyacinth root for methylene blue sorption under dynamic flow conditions. Breakthrough curves were plotted for the methylene blue adsorption on the adsorbent using continuous flow column operation by varying the bed height (0.06?C0.12?m) and the feed concentrations (0.1?C0.2?kg?m^?3). Different column design parameters, such as depth of exchange zone, adsorption rate, and adsorption capacity, were calculated. At the end, an attempt has also been made to model the data generated from column studies using the empirical relationship based on Bohart?CAdams model.     

Microbial and chemical sources of phosphorus supply modulate the yield and chemical composition of essential oil of rose-scented geranium (Pelargonium species) in sodic soils

Rose-scented geranium (Pelargonium sp.) is a highly valued aromatic crop. Its growth is limited by soil salinity and sodicity stress. Arbuscular mycorrhizal (AM) fungus, phosphate-solubilizing bacteria (PSB), and P fertilizers may enhance the growth and secondary metabolism in geranium plants. In this context, a pot experiment was conducted to study the effects of PSB, AM fungi (Glomus intraradices), and P fertilizer on the yield, chemical composition of essential oil, and mineral element acquisition of geranium. The dry matter yield of shoot and essential oil yield, and mineral element (P, K, Ca, Mg, Na, Fe, Cu, and Zn) uptake in shoot tissues of geranium were significantly increased by the inoculation with AM fungi, co-inoculation with AM fungi and PSB, and P fertilization as compared to control. While the co-inoculation of geranium with AM fungi and PSB significantly enhanced the content of the monoterpenes such as citronellol, geraniol, geranial, and a sesquiterpene (10-epi-γ eudesmol), the P fertilization only enhanced the content of a sesquiterpene, 10-epi-γ eudesmol in the volatile oil. We conclude that the co-inoculation of PSB and AM fungi could be the best natural alternative to phosphate fertilizers to enhance the yield and quality of essential oil from geranium plants grown in sodic soils.     

Improvement of Upland Rice Variety by Pyramiding Drought Tolerance QTL with Two Major Blast Resistance Genes for Sustainable Rice Production

Varalu is an early maturing rice variety widely grown in the rainfed ecosystem preferred for its grain type and cooking quality. However, the yield of Varalu is substantially low since it is being affected by reproductive drought stress along with the blast disease. The genetic improvement of Varalu was done by introgressing a major yield QTL, qDTY_12.1, along with two major blast resistance genes i.e. Pi54 and Pi1 through marker-assisted backcross breeding. Both traits were transferred till BC₂ generation and intercrossing was followed to pyramid the two traits. Stringent foreground selection was carried out using linked markers as well as peak markers (RM28099, RM28130, RM511 and RM28163) for the targeted QTL (qDTY_12.1), RM206 for Pi54 and RM224 for Pi1. Extensive background selection was done using genome-wide SSR markers. Six best lines (MSM-36, MSM-49, MSM-53, MSM-57, MSM-60 and MSM-63) having qDTY_12.1 and two blast resistance genes in homozygous condition with recurrent parent genome of 95.0%-96.5% having minimal linkage drag of about 0.1 to 0.7 Mb were identified. These lines showed yield advantage under drought stress as well as irrigated conditions. MSM-36 showed better performance in the national coordinated trials conducted across India, which indicated that improved lines of Varalu expected to replace Varalu and may have an important role in sustaining rice production. The present study demonstrated the successful marker-assisted pyramiding strategy for introgression of genes/QTLs conferring biotic stress resistance and yield under abiotic stress in rice.     

Biomass Industrial Effluent Effect on Carbohydrates, Aminoacids, Nitrite and Nitrite Enzyme Activities of Arachis hypogaea L.

The objectives of the present investigations are to see the effects of biomass power plant effluent on the carbohydrates, aminoacids, nitrite and nitrite enzyme activitiesand proline of Arachis hypogaea L. var TCGS 320 under controlled pot culture methods. Plants were cultivated with 25, 50, 75 and 100% of the effluent and a control without the effluent. The treatment of the crop with 25% of the effluent has shown stimulatory effect on all the biochemical parameters studied. Carbohydrates, starch, aminoacids, protein, nitrate and nitrite reductase enzymatic activities have increased in 10, 15, 20 DAS （days after sowing）. In 25 and 30 DAS all biochemical parameters have decreased, due to environmental factors （rainfall, temperature, humidity, etc.）. The present investigation clearly indicated that the biomass power plant effluent has stimulatory effect on all the biochemical contents at lower concentration, and at higher concentration they have deleterious effects.     

Optimum density of chrysanthemum flower model traps to reduce infestations of Frankliniella intonsa (Thysanoptera: Thripidae) on greenhouse strawberry

In a previous study, we showed that a chrysanthemum flower model trap, developed by modifying an artificial yellow chrysanthemum flower, was more attractive to the flower thrips Frankliniella intonsa Trybom (Thysanoptera: Thripidae) than a commercial yellow sticky trap. In this study, the optimum deployment density of the chrysanthemum flower model trap for reducing thrips infestation was investigated in commercial strawberry greenhouses. The traps were installed within the plant canopy at different densities (0, 5, 10, 20 traps per 50 m² plot) in three greenhouses using a randomized complete block design. The highest density of traps reduced seasonal populations of F. intonsa on strawberry flowers by 82% compared to the untreated control. The traps caught approximately 4.6 times more female than male F. intonsa, though the numbers of females and males in the flowers were similar and were both equally reduced with increasing trap density. A weak correlation (r = 0.54) was found between the number of female F. intonsa trapped and numbers in strawberry flowers, but there was no correlation (r = −0.03) for males. The results indicate flower model trap can be an additional tool for monitoring and/or management tactics against this anthophilous thrips.     

Differential toxicity of Bacillus thuringiensis strains and their crystal toxins against high-altitude Himalayan populations of diamondback moth, Plutella xylostella L

BACKGROUND: Diamondback moth, Plutella xylostella (L.), is a major insect pest of crucifers in the biodiversity‐rich north‐western Indian Himalayan hills. The present investigation was aimed at determining the susceptibility pattern of P. xylostella populations collected from different locations of this region to autochthonous and standard Bacillus thuringiensis strains. RESULTS: Among the reference as well as indigenous B. thuringiensis strains tested, sub spp. kurstaki HD‐1, kurstaki HD‐73, galleriae HD‐8, local galleriae/colmeri strain BtOa1 and some of their Cry1 class toxins were found to be highly toxic. Surprisingly, the sub sp. tolworthi HD‐125, local tolworthi strain BtHa1 and Cry9 class toxins were found to be non‐toxic. Midgut homogenate from fourth‐instar larvae was found to activate 130 kDa protoxin from the local tolworthi strain BtHa1 into 68 kDa toxin, but failed to exert any larval mortality, probably owing to lack of receptor binding. CONCLUSION: The present study provides valuable baseline susceptibility data for the deployment of B. thuringiensis‐based control methods, as well as for future monitoring of development of resistance in P. xylostella to B. thuringiensis in this ecologically sensitive region. Copyright © 2008 Society of Chemical Industry     

Response of upland cotton (<Emphasis Type="Italic">G.hirsutum</Emphasis> L.) genotypes to drought stress using drought tolerance indices

Drought tolerance as such is often not considered to be an independent trait by plant breeders. The objective of this study was to evaluate eight drought tolerance indices, namely stress susceptibility index (SSI), yield stability index (YSI), yield reduction ratio (Yr), yield index (YI), tolerance index (TOL), mean productivity (MP), geometric mean productivity (GMP), and stress tolerance index (STI) in upland cotton (G. hirsutum L.) genotypes. For this purpose, 16 genotypes were sampled during the 2013-2014 growing seasons under both normal and drought-stress field conditions at the Main Cotton Research Station of Navsari Agricultural University, Surat, India. The drought tolerance indices were calculated based on seed cotton yield under drought stress and non-stress conditions. Mean comparison of drought tolerance indices and seed cotton yield validated the significant influences of drought stress on yield as well as significant differences among genotypes. Results of calculated correlation coefficients and multivariate analyses showed that GMP, MP and STI indices were able to discriminate drought-sensitive and tolerant genotypes. Cluster analysis using the drought-tolerance indices divided the 16 genotypes into tolerant and susceptible groups. Two genotypes, G.Cot.16 × H-1353/10 and H-1353/10 × G.Cot.16 gave good yield response under drought conditions leading to their stability during water stress conditions. Based on multivariate analyses using the indices individually or in combinations, it was possible to identify the most yield-stable genotypes across the environments. Overall, we concluded that GMP, MP and STI indices can be efficiently exploited not only for screening drought tolerance but also to identify superior genotypessuitable for both stress and non-stress field conditions.     

Morphophysiological Traits Imparting Salinity Tolerance in Maize (Zea mays L.) Hybrids under Saline Water Irrigation in Vertisols

Maize is categorized as a salt-sensitive crop and identification of fairly salt-tolerant lines is of paramount importance for increasing its production on saline soils. Experiments were conducted in randomized block design with three replications to identify maize accessions showing response to saline water irrigation, traits imparting tolerance, and their effect on yield attributes of maize. Significant variation was present among genotypes for specific leaf area (SLA), potassium (K) content, cob characteristics, yield, biomass, and harvest index. High amount of heritability with large genetic advance indicated the presence of additive gene action for traits like leaf water potential and leaf dry weight. Association analysis revealed high correlation between key traits and direct as well as positive effect of these traits on yield. Principal component analysis resolved three principal components, and high leaf area and water potential were conferring salt tolerance and thus higher yield.     

Vector population manipulation for control of arboviruses – a novel prospect for India

India, the seventh largest country in the world, has diverse geographical and climatic regions with vast rural and peri‐urban areas. Many are experiencing an escalation in the spread and intensity of numerous human diseases transmitted by insects. Classically, the management of these vector‐borne diseases is underpinned by either chemical insecticides and/or environmental management targeted at the vector. However, these methods or their present implementation do not offer acceptable levels of control, and more effective and sustainable options are now available. Genetic strategies for the prevention of arbovirus transmission are most advanced for dengue and chikungunya, targeting their primary vector, Aedes aegypti. The national burden in terms of morbidity and mortality as a direct consequence of dengue virus in India is considered to be the largest worldwide, over 4 times that of any other country. Presently, new genetic technologies are undergoing field evaluation of their biosafety and efficacy in several countries. This paper discusses the merits of these approaches and argues for fair and transparent appraisal in India as a matter of urgency. Identification of any associated risks and their appropriate mitigation are fundamental to that process. © 2013 Society of Chemical Industry