Molecular genetic diversity and population structure of Iranian honey bee (Apis mellifera meda) populations: implications for breeding and conservation

Journal of Plant Diseases and Protection - The honey bee (Apis mellifera), as one of the most important pollinating insects, plays a critical role in biodiversity conservation and global food...     

The effect of organic and chemical fertilizers on oilseed rape productivity and weed competition in short rotation

Abstract

A two-year field experiment was conducted to investigate the impact of short crop rotation and organic amendments on rapeseed yield under weed competition conditions. The primary experimental plots consisted of either triticale or pea as a prior crop, consisting of four subplots with either 25 tons of composted cattle manure (CCM), 150?kg urea N ha^?1 (N), 25 tons composted cattle manure + 75?kg urea N ha^?1 (CCM?+?N), or no urea N or manure added as the control (C0). Rapeseed seed yield was not significantly affected by previous crops, except for rapeseed grown after pea which had slightly higher seed yield (2058?kg ha^?1) than those grown after triticale (1942?kg ha^?1). Plants that received CCM?+?N produced the highest amount of seed yield (2447?kg ha^?1), but were not significantly different from plants that received just urea N (2218?kg ha^?1). Weeds gained more biomass when the previous crop was pea compared to those whose previous crop was triticale. Weeds in plots that received CCM?+?N produced the greatest biomass, followed by N, and CCM plots, respectively.     

Evaluation of different methods for the prediction of saturated hydraulic conductivity in tilled and untilled soils

The larger the bulk density of the soil, the smaller the saturated hydraulic conductivity (K_s), however, the relationship between K_s and dry bulk density for tilled and untilled conditions is different. K_s is lower in tilled soil than in untilled soil with the same texture at the same bulk density. The purpose of this study was to compare different models for the prediction of K_s for two soil textures under both tilled and non-tilled conditions. We compred two models based on the non-similar media concept (NSMC-0, NSMC-1), a model based on the similar media concept (SMC) and a model based on the Kozeny equation and Poiseuille law for prediction of K_s (KC-1 and KC-2). This study was conducted at two areas with loam and silty clay loam soils under tilled and untilled conditions. It is concluded that the SMC model is not able to predict K_s under either tilled or untilled conditions. Further, the NSMC-0 model, along with an equation to estimate the shape factor, was able to predict K_s versus dry bulk density for tilled soils. According to our study, under untilled conditions, the KC-1 and NSMC-1 models, and under tilled conditions, the NSMC-1 and NSMC-0 models, predicted K_s accurately. It is concluded that the NSMC models together with the optimized Kozeny–Carman models could reliably be used to predict K_s in different soil textures.     

Morpho-pomological and chemical properties of pomegranate (Punica granatum L.) cultivars in Iran

This study was conducted to investigate the physico-chemical properties and antioxidant activity of five pomegranate fruit (Punica granatum L.) cultivars grown in Iran. Significant differences were found among the pomegranate cultivars for many of the properties studied. Results showed that, in particular, fruit diameter ranged from 63.63 mm (Syah) to 79.29 mm (Rabab), fruit volume from 153.3 cm³ (Syah) to 293.3 cm³ (Rabab), and fruit density from 0.93 g cm^?3 (Rabab) to 1.13 g cm^?3 (TorshSefeed). Although Syah showed the lowest fruit weight (144.8 g), fruit yield (8.28 ton ha^?1), and fruit skin thickness (1.55 mm), Rabab had the highest fruit yield (27.1 ton ha^?1) and fruit skin thickness (2.32 mm). Juice volume was found to vary between 61.1 and 67.0 cm³. Percent of aril ranged from 59.64% (Rabab) to 75.3% (Syah) and weight of aril between 108.9 and 199.8 g. Also, results indicated that titratable acidity content varied from 0.39% (Syah) to 1.13% (TorshSefeed). The total soluble solids content varied from 12.67 ?Brix (TorshSefeed) to 15.67 ?Brix (ZardehAnar), pH values from 3.05 to 3.77, Electrical conductivity values from 2.8 to 3.14 dS m^?1_, and vitamin C content from 59.25 to 69.52 mg 100 g^?1. The anthocyanin content was observed to vary between 80.36 (Syah) and 216.97 (ZardehAnar). The antioxidant activity of pomegranate cultivars ranged from 27.24% (Syah) to 84.04% (TorshSefeed). These results demonstrated that the cultivar was the major factor which influences the morpho-pomological and chemical (especially, antioxidant activity) properties of pomegranates.     

Growth and yield of lowland rice as influenced by potassium application and cultivation method under alternate wetting and drying water regime

Besides being an essential macronutrient for plant growth, potassium (K) also acts as a stress-relieving agent against various biotic and abiotic stresses, especially water stress. An experiment consisting of three lowland Thai rice varieties (Pathumthani 1, RD57, RD41), two cultivation methods [dry direct seeding (DDS), transplanting (TP)] and four K doses (0, 80, 120,160?kg ha^?1) under alternate wetting and drying (AWD) water regime was conducted to investigate the impact of K and cultivation method on lowland rice varieties subjected to AWD. Pathumthani 1 had significantly higher grain yield at the 120?kg K ha^?1 compared with all other K doses. RD57 and RD41 had maximum grain yield at the 80 and 120?kg K ha^?1, respectively, which was significantly higher than the control; however, grain yield among different K doses was mostly similar for RD57 and RD41. K application at the rate of 120?kg ha^?1 for Pathumthani 1 and 80?kg ha^?1 for RD57 and RD41 could be a feasible option. The performance of DDS and TP was better at the 80 and 120?kg K ha^?1, respectively. Application of K at the optimum dose with proper selection of variety and cultivation method could help in sustainable rice production.     

Effect of protein source and protease addition on performance,blood metabolites and nutrient digestibility of turkeys fed on low-protein diets from 28 to 55 d post hatch

1. The objective of this study was to investigate the effect of a monocomponent protease and dietary inclusion of canola meal (CM) and poultry by-product meal (PBM) on growth performance, carcass characteristics and blood metabolites of turkeys fed on low crude protein (CP) diets from 28 to 55 d post hatch.

2. Experimental treatments included control, maize–soybean meal diet including 258.3 g/kg CP; negative control 1 (NC1), maize–soybean meal diet with reduced CP (232.4 g/kg); NC2, control diet (CP, 258.3 g/kg) including CM (80 g/kg) and PBM (80 g/kg); NC3, maize–soybean meal diet with reduced CP (232.4 g/kg) including CM (80 g/kg) and PBM (80 g/kg). Also, the NC1 + P and NC3 + P diets were created by addition of protease enzyme (30 000 units/kg of diet) to the NC1 and NC3 diets, respectively.

3. The NC3 group had lower body weight gain (BWG) compared to those fed on the control diet, and no improvement with enzyme addition (NC3 + P) was achieved. The protease addition to the NC1 diet (NC1 + P) improved BWG to the level of the control diet. The NC1 group had higher feed conversion ratio (FCR) compared to the control and NC3 + P, but protease addition to the NC1 diet improved FCR.

4. Protease addition to the low CP diets resulted in higher nitrogen (N) retention than in the control and NC2 groups. Also, the NC1 + P and NC3 + P diets increased apparent ileal digestibility (AID) of CP compared to the control group.

5. It was concluded that addition of CM (up to 80 g/kg) and PBM (up to 80 g/kg) to turkey diets had no negative effect on growth performance from 28 to 55 d of age. The NC1 + P group achieved the BWG of the control group which was partially due to increases in N retention and AID of CP, but the NC3 + P group failed to recover the growth losses. This difference implies that the efficacy of the protease may depend upon the protein source in the ration.

     

Evaluation of different media and methods of cultivation on the production and viability of entomopathogenic fungi, Verticillium lecanii (Zimm.) Viegas

For mass production of V. lecanii, three types of cultivation methods including liquid, solid and diphasic production systems were investigated. In the liquid state of production, six media were tested in stationary culture conditions. Among the six media tested, Molasses Yeast Broth (MYB) supported maximum sporulation (8.33 x 10(8) spores mL(-1)) and biomass production (746 mg/100 mL). In the MYB, 4% molasses concentration was found to produce highest spore count (8.56 x 10(8) spores mL(-1)) and biomass (776 mg/100 mL) followed by 5 and 6% molasses. Among the six solid substrates tested, rice grains supported highest spore production (1.14 g/100 g). In diphasic state of production, combination of MYB and rice grains produced the greatest amount of spores, (1.70 g/100 g). Results of this study indicated that diphasic method using MYB as liquid medium and rice as solid substrate are the best method and media for mass production of V1-7 isolate of V. lecanii.     

The effect of the Korea‐US free trade agreement on governance of the aquaculture value chain

We present a value chain analysis of seafood exports from South Korea to major consumer markets in the United States, outlining the global value chain of oyster products from South Korea and its governance structure. A major issue faced by consumers is the lack of ability to determine where and how the seafood products are produced and processed. This can be addressed through standards set by the importing firm or country. In this article, we show that Korea–USA free trade agreement has led to development of high‐capacity US‐approved farms and processing facilities, and stricter standards have created a more efficient production and processing sector for exporting seafood products from Korea to the United States.     

Prediction of soil surface salinity in arid region of central Iran using auxiliary variables and genetic programming

Spatial information on soil salinity is increasingly needed for decision making and management practices in arid environments. In this article, we attempted to investigate soil salinity variation via a digital soil mapping approach and genetic programming in an arid region, Chah-Afzal, located in central Iran. A grid sampling strategy with 2-km distance was used. In total, 180 soil surface samples were collected and then analyzed. A symbolic regression was then adopted to correlate electrical conductivity (EC_e) with a suite of auxiliary data including predicted maps of apparent electrical conductivity (vertical: EC_av and horizontal: EC_ah), Landsat spectral data and terrain attributes derived from a digital elevation model. The accuracy of the genetic programming model was evaluated using root mean square error (RMSE), mean error (ME), and coefficient of determination (R²) based on an independent validation data set (20% of database or thirty soil samples). In general, results showed that EC_ah had the strongest influence on the prediction of soil salinity followed by salinity index wetness index, Landsat Band 3, multi-resolution valley bottom flatness index, elevation, and normalized difference vegetation index. Furthermore, results indicated that the genetic programming model predicted EC_e over the study area accurately (R² = 0.87, ME = ?1.04 and RMSE = 16.36 dSm^?1). Overall, it is suggested that similar applications of this technique could be used for mapping soil salinity in other arid regions of Iran.