Variation in phenotypic characters of pale flax (<Emphasis Type="Italic">Linum bienne</Emphasis> Mill.) from Turkey

The diversity of pale flax (Linum bienne Mill.) as the progenitor of cultivated flax (L. usitatissimum L.) has not been well documented and the domestication syndromes in cultivated flax are poorly understood. An attempt was made to characterize 34 pale flax accessions and six cultivated flax accessions collected during 2007 summer in Turkey. A total of 12 quantitative and 7 qualitative characters covering vegetative and generative plant parts, including phenological traits, were assessed. The occurrence of yellow anthers well known in cultivated flax is reported for the first time in pale flax. Pale flax displayed larger variation in vegetative plant parts and growth habit than the cultivated flax and more heterogeneity within accessions. Within pale flax, a higher degree of variation was observed in many generative parts such as the flower characters than in the capsule and seed characters. Based on the assayed characters, the pale flax from Turkey was grouped into three clusters and these clusters were associated with site elevation and longitude, further confirming local genetic differentiation in pale flax from Turkey. These findings are significant for further studies of flax domestication history and useful for further exploitation of wild flax in genetic improvement of cultivated flax.     

Selective determination of catechin among phenolic antioxidants with the use of a novel optical fiber reflectance sensor based on indophenol dye formation on nano-sized TiO₂

The optical sensor for "tea catechins" was built by immobilizing 2,2'-(1,4-phenylenedivinylene)bis-8-hydroxyquinoline (PBHQ) on TiO? nanoparticles (NPs). The sensor worked by "indophenol blue" dye formation on PBHQ-immobilized TiO? NPs as a result of p-aminophenol (PAP) autoxidation with dissolved O? at pH 10. Among quercetin, rutin, naringenin, naringin, gallic acid, caffeic acid, ferulic acid, p-coumaric acid, catechin, epicatechin, epicatechin gallate, epigallocatechin, epigallocatechin gallate, and trolox, only catechin group antioxidants delayed the color formation on NPs, as measured by the reflectance signal at 710 nm. For quantitative analysis, reflectance signal versus time was recorded, and the difference between the areas under curve (ΔAUC) in the presence and absence of catechin was correlated (r = 0.98) to catechin concentration. The selectivity of the sensor for catechins was shown in tea infusions compared to other plant extracts and was ascribed to the nonplanar structure of catechin interfering with the formation of perfectly conjugated indophenol blue on TiO? surface.     

Investigation of tetracycline and degradation products in Euphrates river receiving outflows of trout farms

In this study, tetracycline (TC), epitetracycline (ETC), 4‐epianhydrotetracycline (EATC) and anhydrotetracycline (ATC) concentrations were determined in the surface waters carrying outflows of trout farms. The samples were taken from downstream of Keban Dam and upstream of Karakaya Dam Lake, which are located in the Euphrates and Tigris River Basin. The occurrence of TC and degradation products (DPs) was proved in the sampling points which take the outflows of the trout farms. Tetracycline and DPs were under the detection limits in sampling points where the trout farms do not exist. The highest TC concentration was detected as 50.0 ± 2.5 μg L^?1 (1st week), whereas the lowest TC concentration was 8.2 ± 0.41 μg L^?1 (7th week). The highest ETC concentration was 88.1 ± 4.4 μg L^?1 (3rd week)and the lowest ETC concentration was 9.4 ± 0.4 μg L^?1 (3rd week). The highest and lowest EATC concentrations were detected as 35.8 ± 1.8 μg L^?1 (2nd week) and 8.2 ± 0.4 μg L^?1 (2nd week) respectively. The highest ATC concentration was 28.3 ± 1.4 μg L^?1 (3rd week), whereas the lowest was 6.54 ± 0.34 μg L^?1 (7th week). Tetracycline and DP concentrations detected in surface waters followed the following order: ETC>TC>EATC>ATC.     

Effect of feeding frequency on growth,feed efficiency and nutrient utilization of juvenile flounder (Platichthys flesus luscus)

An experiment was conducted to determine the effects of optimal feeding frequency on growth performance, feed efficiency, nutrient utilization and body composition in juvenile flounder. Four feeding frequencies of one (F1), two (F2), three (F3) and four (F4) times a day were evaluated as treatments in triplicate for a period of 60 days. Forty-seven hatchery produced juveniles (2.5 ± 0.7 g) were stocked into 160-L rectangular fiberglass tanks and fed with a commercial diet containing 54 % protein to satiation. At the end of the experiment, the final weight of F1, F2, F3 and F4 were 5.06 ± 0.29, 5.91 ± 0.42, 6.24 ± 0.42 and 6.16 ± 0.46 g, respectively. Growth rates and feed consumption were highest in F3 and lowest in F1. Feed conversion ratios ranged between 0.83 ± 0.04 and 0.90 ± 0.03. There were no significant differences in either moisture or ash content of the fish groups. Protein content decreased with increasing feeding frequency, while lipid content partly increased with increasing feeding frequency. Nitrogen intake and lipid intake were significantly higher in fish fed under F3 and F4 treatment, whereas the nitrogen gain decreased and lipid gain increased with increasing feeding frequency. It is concluded that the flounder juveniles can achieve maximum growth performance and better nutrient utilization when they are fed a given ration two times a day. The findings have practical significance toward establishing an appropriate flounder nursery rearing and will directly benefit the nursery operations.     

Effect of synthetic nano-hydroxyapatite as an alternative phosphorus source on growth and phosphorus nutrition of lettuce (Lactuca sativa L.) plant

Phosphorus (P) is one of the least available mineral nutrients to the plants in calcareous and alkaline soils. In this study, we investigated the synthesis, characterization and use of synthetic nano-hydroxyapatite (NHA), P uptake by plants as well as its residual effects. Soluble P source (H₃PO₄) was also included as treatment for comparison. NHA prepared by wet chemical techniques, characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and elemental dispersive X-ray (EDX) analysis. NHA and H₃PO₄ were applied at a rate of 200 mg kg^?1 to find out their effects on phosphorus nutrition and growth of lettuce on the low and high calcareous soil. In addition to this, residual effects of NHA and H₃PO₄ were also determined for lettuce plants grown after first lettuce plants in the both soil. Dry weights of the first and second lettuce plants grown in low and high calcareous soil were significantly increased by applied phosphorus regardless of the source. NHA seems to be more effective than that of ordinary phosphorus source (H₃PO₄-P) on growth and P concentration of the lettuce plants. The promising results of this study needs to be supported with long term field studies regarding the uptake, translocation and interactions of nano-P with the other elements.     

Chemical composition of grape canes

In this study, chemical composition of canes which were sampled from ten different grape cultivars was investigated. For the determination of total phenolics, total flavanols and total flavonol contents, canes were analyzed spectrophotometrically. The phenolic compositions of the canes, including caffeic acid, catechin, p-coumaric acid, epicatechin, gallic acid, luteolin and trans-resveratrol were detected by HPLC. The anthron method was used for the determination of total carbohydrate content. The minerals such as K, P, Ca, Fe, Mg and Zn were determined by ICP-OES. All the parameters investigated in this study significantly changed depending on the cultivar. The results showed that grape canes as agricultural wastes from commercial viticultural activities represent a potentially important source of phenolics, minerals, carbohydrates and proteins. Therefore the grape canes may be used as an easily accessible source of natural antioxidants and food supplement.     

Effect of the burial depth and environmental factors on the seasonal germination of bearded sprangletop (Leptochloa fusca [L.] Kunth ssp. fascicularis [Lam.] N. Snow)

Bearded sprangletop recently was introduced to Turkey, where it has adapted to rice cultivation and become an important weed in many regions of the country. Experiments were conducted to determine the effects of light, temperature, osmotic stress, salt stress, pH and flooding on bearded sprangletop germination and emergence. Mature bearded sprangletop seeds were collected from rice fields in August 2008. Approximately 1250 seeds were wrapped in plastic fabric and buried at 2 or 10 cm in pots in flooded or non‐flooded conditions. In this experiment, seed germination in the light from the flooded and non‐flooded treatments began in the spring, peaked in summer and decreased in the fall. This pattern was repeated the following year after exposing the seeds to natural seasonal temperature changes. As either the level of water stress or NaCl concentration increased, cumulative seed germination decreased. No seed germinated when the NaCl concentration exceeded 400 mole. The level of seedling emergence decreased with an increasing burial depth. Under the flooded conditions, emergence began in late April and continued until early July, with peak emergence in the first week of June. Under the non‐flooded conditions, bearded sprangletop emerged later than under the flooded conditions and the overall level of emergence was lower. The depth of burial and water stress appear to be the most important factors that limit seed germination. Germination was stimulated by light, suggesting that the seeds are positively photoblastic.     

Solution electrospinning of polypropylene-based fibers and their application in catalysis

Since the dissolution of polyolefins is a chronic problem, melt processing has been tacitly accepted as an obligation. In this work, polypropylene (PP) was modified on molecular level incorporating poly(ethylene glycol) (PEG) as graft segment (PP-g-PEG) in a range of 6 to 9 mol%. Gold nanoparticles were nucleated in the presence of the copolymer chains via redox reaction. The dissolution of the amphiphilic comb-type graft copolymers containing gold nanoparticles (80 nm in diameter) was achieved in toluene and successfully electrospun from its solution. The diameter of composite fibers was in the range from 0.3 to 2.5 μm. The design of the structurally organized copolymer fiber mats provided a support medium for the nanoparticles enhancing the active surface area for the catalytic applications. The resulting composite fibers exhibited rapid catalytic reduction of methylene blue (MB) dye in the presence of sodium borohydride (NaBH₄) compared to corresponding composite cast film.