Growth response of the salt-sensitive and the salt-tolerant sugarcane genotypes to potassium nutrition under salt stress

Adequate regulation of mineral nutrients plays a fundamental role in sustaining crop productivity and quality under salt stress. We investigated the ameliorative role of potassium (K as K₂SO₄) in overcoming the detrimental effects of sodium chloride (NaCl) on sugarcane genotypes differing in salt tolerance. Four levels of NaCl (0, 100, 130 and 160 mM) were imposed in triplicate on plants grown in gravel by supplying 0 and 3 mM K. The results revealed that application of NaCl significantly (p ≤ 0.05) increased sodium (Na⁺) but decreased K⁺ concentrations in shoots and roots of both genotypes with a resultant decrease in K⁺/Na⁺ ratios. Physical growth parameters and juice quality were also markedly reduced with increasing NaCl concentrations compared with controls. However, addition of K alleviated the deleterious effects of NaCl and improved plant growth under salt stress. Cane yield and yield attributes of both genotypes were significantly (p ≤ 0.05) higher where K was added. Juice quality was also significantly (p ≤ 0.05) improved with the application of K at various NaCl levels. The results suggested that added K interfered with Na⁺, reduced its uptake and accumulation in plant tissues and consequently improved plant growth and juice quality in sugarcane.     

Valuation of gamma irradiation for proficient production of parasitoids (Hymenoptera: Chalcididae & Eucoilidae) in the management of the peach fruit-fly,Bactrocera zonata (Saunders)

Recognizing the potential significance of using nuclear techniques in biological control, investigations were conducted on the rearing of parasitoids of the peach fruit-fly, Bactrocera zonata (Saunders) (Diptera: Tephritidae) to lead to a greater flexibility in the use of irradiated hosts. For improving mass production of the biological control agents, the use of irradiated fruit-fly larvae at the dose of 15 Gy proved useful for enhancing the parasitism and adult emergence of the larval parasitoid, Trybliographa daci (Weld) (Hymenoptera: Eucoilidae) due to no negative repercussions on parasitoid development. Overall, parasitism by the parasitoid increased with age of the host larvae; however, significantly higher parasitism occurred on 4 d-old irradiated larvae of B. zonata compared to those aged 5 d. The female parasitoids preferred the irradiated larvae, and significantly higher numbers of larvae were parasitized compared with non-irradiated larvae. There was no significant difference in adult parasitoid emergence with respect to the sex of the host. A radiation level of 80 Gy was the best dose for rearing of the pupal parasitoid, Dirhinus giffardii (Silvestri) (Hymenoptera: Chalcididae) owing to broad tolerances in the use of irradiation for the rearing of fruit-fly's parasitoids. Percentage parasitism by D. giffardii varied with host pupal age, and the preference of the female parasitoid was lower on 48 h old host pharate pupae due to optimum size and mass of host. Present findings further revealed that the 24 h old host pupae of B. zonata were relatively more suitable for the maximum parasitism and progeny production of D. giffardii. Parasitisms by D. giffardii and T. daci were significantly higher on B. zonata host when parasitoids were released at a density of 3000 individuals per acre (7500 per hectares) than the other release rates of parasitoids for the management of fruit-flies in mango orchards. The implementation of these findings ought to help improve the mass production of parasitoids and the effectiveness of releases of biocontrol agents for control of B. zonata in mango plantations.     

Jasmonic and salicylic acid-induced resistance in sorghum against the stem borer Chilo partellus

Induced resistance was studied in three sorghum genotypes (IS2205, ICSV1 and ICSV700) against Chilo partellus (Swinhoe) (Lepidoptera; Pyralidae) infestation and jasmonic acid (JA) and salicylic acid (SA) application. The activity of plant defensive enzymes [peroxidase (POD), polyphenol oxidase (PPO), superoxide dismutase (SOD), and catalase (CAT)], and the amounts of total phenols, hydrogen peroxide (H₂O₂), malondialdehyde (MDA), and proteins were recorded at 6 days after infestation. The induction of enzyme activities and the amounts of secondary metabolites varied among the genotypes and treatments. The genotype IS2205 showed a stronger effect than that of ICSV1 or ICSV 700. Treatment with JA followed by insect infestation induced greater levels of enzymes and secondary metabolites. The results suggest that JA induces greater levels of resistance components in sorghum plants against insect pests. Thus, pretreatment of plants with elicitors including JA and SA could provide a greater opportunity for plant defense against herbivores.     

Effect of a Previous Washing Step with Tannic Acid on the Quality of Minced Horse Mackerel (Trachurus trachurus) During Frozen Storage

Fatty fish have been recognized as potential raw material for production of minced meat; however, they are prone to oxidation and further deterioration. In the present study, the effect of washing and antioxidant (tannic acid) treatment on the quality of minced meat of Trachurus trachurus (horse mackerel) during frozen storage was observed. Minced meat of Trachurus trachurus was divided into three lots (T0, T1, and T2). T1 was washed with cold water, T2 with cold water containing tannic acid (100 mg/kg), and T0 was not washed. All the lots were frozen at ?40°C and stored at ?20 ± 2°C for 125 days and were subjected to biochemical, microbiological, and sensory evaluation at regular intervals of 25 days. The antioxidant treatment with tannic acid at the dosage used was found effective in minimizing the rancidity problems of minced meat (T2), compared to T0 and T1. During the whole period of storage, samples from T2 showed good quality in terms of microbiological, biochemical, and sensory analysis compared to T1 and T0.     

Global marine yield halved as fishing intensity redoubles

There is widespread concern and debate about the state of global marine resources and the ecosystems supporting them, notably global fisheries, as catches now generally stagnate or decline. Many fisheries are not assessed by standard stock assessment methods including many in the world's most biodiverse areas. Though simpler methods using widely available catch data are available, these are often discounted largely because data on fishing effort that contributed to the changes in catches are mostly not considered. We analyse spatial and temporal patterns of global fishing effort and its relationship with catch to assess the status of the world's fisheries. The study reveals that fleets now fish all of the world's oceans and have increased in power by an average of 10‐fold (25‐fold for Asia) since the 1950s. Significantly, for the equivalent fishing power expended, landings from global fisheries are now half what they were a half‐century ago, indicating profound changes to supporting marine environments. This study provides another dimension to understand the global status of fisheries.     

Field evaluation and fiber analysis of transgenic cotton

We report the field evaluation of second generation of transgenic cotton expressing Bacillus thuringiensis (Bt) genes cry1Ac and cry2A under CaMV 35S promoter. Sixty-five transgenic lines were grown under RCBD design. Transgenic plants exhibited inherent ability to resist target insect (p < 0.05 and 0.01). Morphological studies showed significant reduction in plant height making them favorable for breeding. Yield was significantly increased for the transgenic lines. Fiber analysis showed improved gin turn out 40% for transgenic lines in comparison to 32% for non-transformed lines. Fibre quality of transgenic lines was not affected when compared with non transgenic lines. Inheritance pattern for transgenic lines suggests the need of further studies to understand the complex molecular mechanisms for resistance management and biosafety studies to develop new Bt cotton varieties.     

Evaluation of Three Chitin Metal Silicate Co-Precipitates as a Potential Multifunctional Single Excipient in Tablet Formulations

The performance of the novel chitin metal silicate (CMS) co-precipitates as a single multifunctional excipient in tablet formulation using direct compression and wet granulation methods is evaluated. The neutral, acidic, and basic drugs Spironolactone (SPL), ibuprofen (IBU) and metronidazole (MET), respectively, were used as model drugs. Commercial Aldactone^®, Fleximex^® and Dumazole^® tablets containing SPL, IBU and MET, respectively, and tablets made using Avicel^® 200, were used in the study for comparison purposes. Tablets of acceptable crushing strength (>40 N) were obtained using CMS. The friability values for all tablets were well below the maximum 1% USP tolerance limit. CMS produced superdisintegrating tablets (disintegration time < 1 min) with the three model drugs. Regarding the dissolution rate, the sequence was as follow: CMS > Fleximex^® > Avicel^® 200, CMS > Avicel^® 200 > Dumazole^® and Aldactone^® > Avicel^® 200 > CMS for IBU, MET and SPL, respectively. Compressional properties of formulations were analyzed using density measurements and the compression Kawakita equation as assessment parameters. On the basis of DSC results, CMS co precipitates were found to be compatible with the tested drugs. Conclusively, the CMS co-precipitates have the potential to be used as filler, binder, and superdisintegrant, all-in-one, in the design of tablets by the direct compression as well as wet granulation methods.     

Effects of incubation times and moisture regimes on pH values and exchangeable cations in acid sulfate soils as influenced by application rates of basic slag

Severe acidifications in acid sulfate soils (ASSs) have occurred worldwide due to sulfuric acidity, which requires sustainable measures for their reclamation. Accordingly, an incubation study was conducted with the topsoil of two different ASSs (Cheringa and Badarkhali) to evaluate the effects of basic slag (BS; size <1 mm, pH 9.6, Ca 20.8%, Mg 9.8%, etc.), on reduction of acidity and changes in exchangeable cations. It is noted that BS is a byproduct of steel industry in Bangladesh and can be collected almost free of charge. These soils received BS at the rate of 0 (T₀), 11 (T₁), 22 (T₂) and 33 (T₃) t ha⁻¹ under various moisture regimes (saturated condition M₁,_, i.e., 100% moisture content, wetting–drying cycles of 100 and 50% moisture M_2, and moisture at field condition M₃, i.e., 50%). The impacts of these treatments on some selected parameters in these soils were studied within 180 days of incubation. The application of BS was found to increase the pH of soils from 3.6 to 5.1 for Cheringa, 3.9 to 5.2 for Badarkhali soils at the end of incubation. These increments were more striking with the highest doses of BS under saturated moisture conditions in both of the soils. The ECe of the soils was not much influenced by the application of BS regardless of time. The treatments exerted significant (P ≤ 0.05) effects on exchangeable cations in different periods of incubation. The striking changes were recorded for the rate of increments of Ca²⁺ and Mg²⁺, which were about 2–3 times higher for Ca and more than 2 times higher for Mg²⁺ compared with the control after 180 days of incubation. These results suggest that the application of BS not only increased the Ca²⁺ to the higher amount than that of the increment of Mg²⁺ in the soils, but also improved one of the important criteria of Ca²⁺ and Mg²⁺ ratio in the soils.     

Use of Canopy Temperature Measurements as a Screening Tool for Drought Tolerance in Spring Wheat

Remotely sensed infrared canopy temperatures provide an efficient method for rapid, non-destructive monitoring of whole-plant response to water stress. Field studies were conducted in 1992 and 1993 to evaluate the potential for using canopy temperatures to screen for drought tolerance in wheat. In both years, 12 spring wheat (Triticum aestivum L.) genotypes were grown under two irrigation levels (well-watered and moisture-stressed) imposed between tillering and anthesis with a line-source sprinkler irrigation system. Canopy temperature measurements were taken in well-watered and moisture-stressed plots between 1330 and 1430 h (MDT) on five clear days in 1992 and seven clear days in 1993 during the late vegetative and early reproductive growth periods following closure of the plant canopy. Genotypes exhibited differences in mean canopy temperatures across the two irrigation levels and two years. Klasic consistently had the highest canopy temperature under moisture-stressed conditions, while Bannock and Pondera had the lowest. Bannock, Yecora Rojo and Klasic had the warmest canopies under well-watered conditions, while Vandal, Amidon and Rick had the coolest. Plot-to-plot variation in canopy temperature under water stress conditions was evident for differences in grain yield. Significant correlations between canopy temperature and yield under moisture-stress conditions and drought susceptibility index values indicated the potential for screening wheat genotypes for drought response.