Nonparametric phenotypic stability analysis in advanced barley (<Emphasis Type="Italic">Hordeum vulgare</Emphasis> L.) genotypes

The development of genotypes with adaptation to a wide range of environments is one of the most important goals of plant breeding programs. In order to compare nonparametric stability measures and to identify promising high-yield and stable barley (Hordeum vulgare L.), 20 barley genotypes selected from the Iran/ICARDA joint project and grown in nine environments during 2009-11 in Iran. Four nonparametric statistical tests of significance for genotype × environment (GE) interaction and 10 nonparametric measures of stability were used to identify stable genotypes in nine environments. Results of nonparametric tests of G×E interaction (Kubinger, Hildebrand, and Kroon/ Laan) and a combined ANOVA across environments, indicated the presence of both crossover and non-crossover interactions. Also, only TOP and rank-sum values were positively associated with high yield. Thus, in the simultaneous selection for high yield and stability, only the rank-sum and TOP methods were useful in terms of the principal component analysis results, and correlation analysis of nonparametric stability statistics and yield. According to these stability parameters (TOP and rank-sum), three genotypes (G13, G12, and G17) were the most stable for grain yield. The results also revealed that based on nonparametric test results, stability could be classified into three groups, according to agronomic and biological concepts of stability.     

Precipitation forecasting by large-scale climate indices and machine learning techniques

Global warming is one of the most complicated challenges of our time causing considerable tension on our societies and on the environment. The impacts of global warming are felt unprecedentedly in a wide variety of ways from shifting weather patterns that threatens food production, to rising sea levels that deteriorates the risk of catastrophic flooding. Among all aspects related to global warming, there is a growing concern on water resource management. This field is targeted at preventing future water crisis threatening human beings. The very first stage in such management is to recognize the prospective climate parameters influencing the future water resource conditions. Numerous prediction models, methods and tools, in this case, have been developed and applied so far. In line with trend, the current study intends to compare three optimization algorithms on the platform of a multilayer perceptron (MLP) network to explore any meaningful connection between large-scale climate indices (LSCIs) and precipitation in the capital of Iran, a country which is located in an arid and semi-arid region and suffers from severe water scarcity caused by mismanagement over years and intensified by global warming. This situation has propelled a great deal of population to immigrate towards more developed cities within the country especially towards Tehran. Therefore, the current and future environmental conditions of this city especially its water supply conditions are of great importance. To tackle this complication an outlook for the future precipitation should be provided and appropriate forecasting trajectories compatible with this region's characteristics should be developed. To this end, the present study investigates three training methods namely backpropagation (BP), genetic algorithms (GAs), and particle swarm optimization (PSO) algorithms on a MLP platform. Two frameworks distinguished by their input compositions are denoted in this study: Concurrent Model Framework (CMF) and Integrated Model Framework (IMF). Through these two frameworks, 13 cases are generated: 12 cases within CMF, each of which contains all selected LSCIs in the same lead-times, and one case within IMF that is constituted from the combination of the most correlated LSCIs with Tehran precipitation in each lead-time. Following the evaluation of all model performances through related statistical tests, Taylor diagram is implemented to make comparison among the final selected models in all three optimization algorithms, the best of which is found to be MLP-PSO in IMF.     

Nutrition Management and Farm’s Age Affect Saffron Daughter Corms Behavior,Nutrients Uptake and Economic Water and Fertilizer Use Efficiency: A Large Scale On-farm Experiment in Torbat Heydarieh,Iran

ABSTRACT

Evaluation of the relationships between nutritional patterns and farms’ age with the behavior of saffron (Crocus sativus L.) daughter corms based on farmers’ management (on-farm) can be crucial in improving saffron sustainable yield. Furthermore, in commercial saffron production, especially in small farms, the purchased water and fertilizers are the basis of sustainable saffron profitability, hence, recognizing the relationships between economic water use efficiency (EWUE) and economic fertilizer use efficiency (EFUE) can be important. An on-farm experiment was conducted on a large scale based on farmers’ management in Torbat Heydarieh, Iran. The farms’ age (1–6 years old) and fertilizers management approaches (organic, mineral and integrated) were considered as the first and second factors, respectively. Large-sized daughter corms number and weight and corms N and P content increased with increasing farms’ age from 1 to 4 years old. However, these parameters decreased with increasing farms’ age from 4 to 6 years old. Irrespective of saffron farms’ age, the minimum large-sized daughter corms number and weight were observed when mineral fertilizer management was practiced. By contrast, the maximum values were related to integrated fertilizer management. In each type of fertilizer management, EWUE and EFUE (based on large-sized daughter corms monetary value) increased with increasing farms age from 1 to 4 years. However, increase in farms age from 4 to 6 years caused a significant reduction in mentioned indices. Overall, if high-quality saffron corm production is needed, corms should be harvested in the fourth year to gain the maximum yield and profit.     

Effects of dietary supplemental methionine source and betaine replacement on the growth performance and activity of mitochondrial respiratory chain enzymes in normal and heat‐stressed broiler chickens

This study aimed to evaluate the effects of dietary supplemental methionine (Met) source and betaine (Bet) replacement for Met on performance and activity of mitochondrial respiratory chain enzymes (MRCEs) in normal and heat‐stressed broiler chickens. Total of 1,200‐day‐old Ross 308 chicks were allocated to two houses, each consisted of 12 treatments, five replicates of 10 birds each with 2 × 2×3 × 2 (temperature × Met source × Met level × Bet, respectively) split‐plot factorial arrangement. Met level in the basal diets was 70% requirements (Req) that was increased to the requirement or 130% by supplemental dl ‐ or l ‐Met. Bet was or was not substituted at the rate of 30% supplemental dl ‐ or l ‐Met. Feed conversion ratio (FCR) in chicks fed 70% l ‐Met was lower than those fed 70% dl ‐Met diet during 1–10 days (p = 0.04). Broilers fed diets containing requirement or 130% Met, regardless of its source, showed higher weight gain (WG) than those received 70% Met diet during 11–42 days (p < 0.001). Feed intake (FI) of broilers fed 130% Met diet was decreased compared to other two groups during 11–42 days (p < 0.05). One hundred thirty percent Met requirement diet resulted in lower FCR comparing to other two groups during 11–42 days (p < 0.001). Heat‐stressed birds grew less than those under normal condition (p < 0.05). Broilers fed Req Met diet under normal temperature exhibited higher activities of complexes (Cox) I and III (p < 0.05). Cox I activity in heat‐stressed birds fed Bet + diet was similar to those fed Bet‐diet under normal temperature (p = 0.046). It is concluded that performance and the activities of Cox I and III were increased as the level of Met increased. Bet replacement for 30% supplemental Met resulted in similar consequences comparing to non‐Bet replacement diets on performance, but increased the activity of Cox III. l ‐Met was effective than dl ‐Met at the cellular level. High ambient temperature depressed performance and MRCE activity.     

Effects of dietary myrcene administration on antioxidant gene responses in common carp (Cyprinus carpio), exposed to copper sulphate

In the present study, common carp (Cyprinus carpio) were fed with diet supplemented with 0% (M0) or 0.5% (M0.5) myrcene for 6 week and exposed to ambient copper (0.2 mg/L) for further 2 weeks. Gene expressions of superoxide dismutase (sod), catalase (cat), glutathione peroxidase (gpx), glutathione reductase (gr) and glutathione S‐transferase (gst) were assayed in the fish brain and kidney, and thiobarbituric reactive substance (TBARS) levels were determined in blood plasma. The results showed that there was no significant difference in TBARS levels between the M0 and M0.5 treatments, before the copper exposure; however, the M0 had significantly higher TBARS levels compared to the M0.5, after the copper exposure. The antioxidant genes showed different patterns in the fish brain and kidney. The genes were up‐regulated in the fish brain by dietary myrcene and copper exposure. However, in the fish kidney, the M0.5 treatment showed no change in sod, cat, gpx before and after the copper exposure. The results suggest that myrcene is capable to induce antioxidant enzymes that prepare the fish for a further oxidative condition (i.e. copper exposure). Dietary myrcene at 0.5% level is suggested for common carp before treatment with copper sulphate.     

Effects of dietary tryptophan levels and fish stocking density on immunological and antioxidant responses and bactericidal activity against Aeromonas hydrophila in rainbow trout (Oncorhynchus mykiss)

Rainbow trout (Oncorhynchus mykiss) was reared under low (LD) and high (HD) stocking densities for 70 days, during which they were fed with diets supplemented with 0, 5 and 10 g tryptophan (Trp) per kg. At the end of the experiment, there were significant interaction effects of the stocking density and Trp levels on plasma Trp, globulin, lysozyme, catalase (CAT), malondialdehyde (MDA), and bactericidal activity and blood leucocyte count. However, there was no difference in plasma complement (ACH50), total immunoglobulin (Ig), total antioxidant capacity (TAC), superoxide dismutase (SOD) and blood differential leucocyte count. Trp at 5 g per kg diet significantly increased lysozyme and bactericidal activity, and decreased MDA under both the LD and HD conditions. Moreover, it significantly increased plasma CAT and blood leucocyte under the LD and HD conditions respectively. Trp at 10 g per kg diet significantly increased blood leucocyte and plasma bactericidal activity under the LD condition, but significantly decreased plasma globulin and bactericidal activity under the HD condition. In conclusion, the present results showed that the effects of Trp on immune and antioxidant systems depend on Trp levels and stressful conditions. As 5 g Trp per kg diet is beneficial for rainbow trout well‐being under both the LD and HD conditions, higher level of Trp (10 g/kg) is not beneficial and even causes some negative effects under the HD condition.     

Dietary ginger administration attenuates oxidative stress and immunosuppression caused by oxytetracycline in rainbow trout (Oncorhynchus mykiss)

In the present study, potential ameliorative effects of dietary ginger (GN) were investigated on antioxidant and immune responses of rainbow trout (Oncorhynchus mykiss) during oxytetracycline (OX) administration. As a 2 × 3 factorial design, the fish were orally treated with OX (a daily dose of 100 mg/kg) and GN (either 10 or 20 g/kg diet) for 10 days. Then, blood samples were taken from each treatment to monitor plasma lysozyme, complement (ACH50), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione‐S‐transferase (GST) activities, and reduced glutathione (GSH), malondialdehyde (MDA), total immunoglobulin (Ig) and globulin levels. OX treatment significantly decreased SOD (30%), GPx, (10%) and lysozyme (23%) activities, and GSH (19%) levels; however, it increased GST (16%) activity and MDA (28%) levels. Ten grams GN per kg levels significantly decreased SOD (35%), CAT (13%), GST (20%) and MDA (30%), but increased GSH (30%), lysozyme (48%) and globulin (16%). Twenty grams GN per kg diet significantly decreased SOD (26%) and MDA (17%), but increased lysozyme (31%) levels. Interaction effects of dietary GN and OX were observed on plasma MDA and GPx levels, as 10 g GN per kg diet prevented the OTC‐induced changes in these parameters. Moreover, 20 g GN per kg diet prevented the OX‐induced change in GPx activity and mitigated the MDA elevation by 20%. It is concluded that GN administration at 10 g/kg diet is beneficial in mitigating oxidative stress and immunosuppression of rainbow trout during OX administration.     

Rainbow trout (<Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis>) anesthesia with myrcene: efficacy and physiological responses in comparison with eugenol

The aim of the present study was to investigate anesthetic efficacy of myrcene in rainbow trout (Oncorhynchus mykiss) along with the fish biochemical response to anesthesia in comparison with eugenol. In the first experiment, 240 fish were stocked in 12 tanks and acclimatized to experimental conditions for 2 weeks. Then, the fish of each tank were subjected to one concentration of either eugenol (12, 20, 30, 50, 80, and 130 μL/L) or myrcene (100, 150, 200, 300, 400, and 500 μL/L) concentrations. Induction time of and recovery time from anesthesia were recorded for each fish separately. Using these results, desired concentrations to induce anesthesia within 60, 180, 300, and 600 s were determined, being 81, 30, 19, and 10 μL/L eugenol and 531, 251, 177, and 111 μL/L myrcene. In the second experiment, 96 fish were stocked in 8 tanks. Six fish were netted from each tank and exposed to the calculated eugenol or myrcene concentrations. Blood samples were taken after the fish reached anesthesia. The results showed that there was no significant difference in serum lactate, alanine transaminase, and alkaline phosphatase. Increase in the induction time of anesthesia resulted in increased serum glucose with no significant difference between the anesthetics. Increase in induction time of anesthesia led to increase in serum lactate dehydrogenase activity in the eugenol-anesthetized fish and aspartate transaminase activity in myrcene-anesthetized fish. In conclusion, myrcene is capable to anesthetize rainbow trout, but at higher concentrations compared to eugenol. In addition, biochemical analysis showed that increase in induction time of anesthesia leads to hyperglycemia and increase in AST and LDH activities depending on anesthetic type.