Development of osmoregulatory tissues in the Lake van fish (<Emphasis Type="Italic">Alburnus tarichi</Emphasis>) during larval development

Lake Van is one of the largest alkaline lakes worldwide and Lake Van Fish (Alburnus tarichi Güldenstädt, 1814) is the only vertebrate species inhabiting it. Lake Van Fish is an anadromous species that migrates to the streams (salinity 0.02%, pH 8.42) flowing into Lake Van (salinity 0.22%, pH 9.8) during the spawning period (April–July). Following spawning, fish return to Lake Van while larvae remain in fresh water. This study examined the development of osmoregulatory organs and the distribution of ionocytes in Lake Van Fish larvae adapting to the highly alkaline water characterizing the lake. Ionocytes were marked immunohistochemically and observed in whole mounts with immunofluorescence staining using the Na⁺/K⁺ ATPase antibody. Ionocytes were first identified in the yolk sac membrane and skin, and then in the gills, digestive tract, and kidneys of larvae. The number of ionocytes on yolk sac membrane and skin decreased during larval development, indicating ionocytes on these tissues have a role in larvae osmoregulation. Larvae hatched from eggs in stream waters die when transferred to Lake Van water but survived in lake water diluted with deionized water. Thus, larvae need to go through certain alterations at the cellular and organ levels in order to adapt to the conditions of Lake Van water, indicating they do not enter this lake immediately after hatching.     

Effect of Different Nitrogen Doses on Dry Matter Ratio,Chlorophyll and Macro/Micro Nutrient Content in Sweet Herb (Stevia rebaudiana Bertoni)

With this study, the effect of different nitrogen (N) doses applied to sweet herb (0, 50, 100, 150 and 200 N kg ha^?1) on the macro/micro nutrient element content, dry matter ratio and on the chlorophyll amount in the plant leaves is examined. The research was carried out in the research and trial field of Faculty of Agriculture Agronomy department, Akdeniz University, during the 2012–2013 growing season under field conditions for 2 years with four replications according to the randomized block trial design. Chlorophyll amounts were determined and the average was obtained with three readings from each leaf by a chlorophyll meter when the plants were in the beginning of flowering. Post-harvest macro and micro nutrient elements of the sweet herb were also investigated. According to the obtained data, while the highest chlorophyll and N amounts in the leaf for both the first and second years were determined as 46.97 SPAD (Minolta Corp, NJ, USA) and 1.34 N% 44.9 SPAD, 1.42 N%, respectively, under 200 kg ha^?1 N application, the lowest chlorophyll and N amounts were determined in the control group. In addition, N application in different doses for both years increased the phosphorus (P) and potassium (K) contents and increased the microelement contents, especially in the second year. At the same time, a correlation between the chlorophyll content in the plant leaves and the N amount was determined and a linear increase was observed in the chlorophyll amount with the increased green part.     

Identification of resistance to bacterial canker (<Emphasis Type="Italic">Pseudomonas syringae</Emphasis> pv. <Emphasis Type="Italic">syringae</Emphasis>) disease on apricot genotypes grown in Turkey

Bacterial canker caused by Pseudomonas syringae pv. syrinage (Pss) in apricot has widely spread in Turkey, especially in Malatya province, in recent years. The main objective of this study was to determine resistance of apricot cultivars to bacterial canker caused by Pss in apricot cultivars grown in Turkey. During the 2006–2007 growing period, bacterial isolations were taken from diseased apricot trees in Malatya and 53 Pseudomonas syringae isolates were obtained. Forty-two isolates were determined as Pseudomonas syringae pv. syringae and 11 isolates as pv. morsprunorum. In a pathogenicity test, leaves of cv. Hacihalilo?lu were used and five Pss isolates (K24, K25, K43, K47 and K51) were detected to be the most virulent and were used to test for cultivar resistance to Pss. Leaves of fifteen apricot cultivars (Alyanak, Çatalo?lu, Çölo?lu, Erken A?erik, Hacihalilo?lu, Hasanbey, ?smaila?a, Kabaa?i, Karacabey, Sakit 2, So?anci, ?am, ?ekerpare, Tokalo?lu (Erzincan) and Turfanda Eski Malatya) were tested for resistance to Pss. Green shoots were spray-inoculated with a concentration of 10⁸ cfu ml^?1 Pss mixed culture. Sprayed shoots were covered with moist plastic bags for 3 days and maintained in the growth chamber and monitored for symptom development. Hasanbey, Çölo?lu, So?anci and ?ekerpare apricot cultivars were resistant and ?am, Tokalo?lu (Erzincan) and Erken A?erik apricot cultivars were susceptible to Pss. This is the first report of a resistance source in apricot cultivars grown in Turkey against Pss.     

Promotion by 5-aminolevulenic acid of pepper seed germination and seedling emergence under low-temperature stress

The effects of incorporating 5-aminolevulenic acid (ALA) into the priming solution on low-temperature germination and emergence percentage performance of red pepper (Capsicum annuum cv. Sena) seeds before and after seed storage were investigated. Seeds were primed in 3% KNO₃ solution for 6 days at 25 °C in darkness containing 0 ppm, 1 ppm, 10 ppm, 25 ppm, 50 ppm or 100 ppm ALA. Following priming, seeds were either immediately subjected to germination and emergence tests at 15 °C or stored at 4 °C or 25 °C for 1 month after which they were subjected to germination and emergence tests at 15 °C. Priming pepper seeds in the presence of ALA improved final germination percentage (FGP) and germination rate (MGT) at 15 °C compared to non-primed seeds. The highest FGP was obtained from seeds primed in the presence of 25 ppm and higher ALA concentrations while the highest MGT was obtained from seeds primed in KNO₃ supplemented with 10 ppm ALA. Emergence percentages were the highest for the seeds primed in the presence of 25 ppm ALA and 50 ppm ALA while non-primed seeds had the lowest emergence percentage. Highest emergence rates (MET) and heaviest seedlings were also obtained from seeds primed in KNO₃ supplemented with 50 ppm ALA. Although all priming treatments improved germination and emergence performance of pepper seeds at 15 °C following 1 month of storage under two different temperatures, inclusion of 25 ppm and 50 ppm ALA into the priming solution resulted in higher germination and emergence percentages and faster germination and emergence compared to seeds primed in KNO₃ only and non-primed seeds. These results indicate that priming seeds in 25 ppm and 50 ppm ALA incorporated into the KNO₃ solution can be used as an effective method to improve low-temperature performance of red pepper seeds and that these seeds can be stored for 1 month at 4 °C or 25 °C and still exhibit improved germination and emergence performance at 15 °C.     

Physico-chemical changes during growth of persimmon fruits in the East Mediterranean climate region

Physico-chemical changes were monitored during growth of pollination variant non-astringent ‘Harbiye’ persimmon fruits (Diospyros kaki L.) grown at low or high altitude of the East Mediterranean Region of Turkey for two growing seasons (2001–2002 and 2002–2003). Fruit growth in diameter followed a typical double sigmoid curve, consisting of two rapid growth stages, stage I and stage III, separated by a period of slow growth (stage II) at both altitudes. The durations of stages I, II and III were 105–119, 21–35 and 21–42 days, respectively, at low and high altitude. ‘Harbiye’ persimmons showed significant decreases in soluble tannin concentration and total carotenoid content during stage I. At the end of stage I, ‘Harbiye’ persimmons became non-astringent. Stage II was characterized with slow growth, the beginning of acid degradation and a significant increase in total sugars, especially in the sucrose component. At end of stage II, the fruit began to turn yellow-orange, indicating the occurrence of colour break. The greatest increase in total soluble solids (TSS) content occurred in the final month before harvest during stage III when pronounced changes in skin colour and softening of fruits were observed. The 175 and 168 days after full bloom (DAFB) at low and high altitudes, respectively, are appropriate timing for harvest of the ‘Harbiye’ persimmon fruits in the East Mediterranean region. At these stages, ‘Harbiye’ persimmon fruits reached the best quality for consumers.     

Development of flexible antimicrobial packaging materials against Campylobacter jejuni by incorporation of gallic acid into zein-based films

In this study, antimicrobial films were developed against Campylobacter jejuni by incorporation of gallic acid (GA) into zein-based films. The zein and zein-wax composite films containing GA between 2.5 and 10 mg/cm(2) were effective on different C. jejuni strains in a concentration-dependent manner. Zein and zein-wax composite films showed different release profiles in distilled water but quite similar release profiles at solid agar medium. Depending on incorporated GA concentration, 60-80% of GA released from the films, while the remaining GA was bound or trapped by film matrix. The GA at 2.5 and 5 mg/cm(2) caused a considerable increase in elongation (57-280%) of all zein films and eliminated their classical flexibility problems. The zein-wax composite films were less flexible than zein films, but the films showed similar tensile strengths and Young's modulus. Scanning electron microscopy indicated different morphologies of zein and zein-wax composite films. This study clearly showed the good potential of zein and GA to develop flexible antimicrobial films against C. jejuni.     

Remediation of lead-, arsenic-, and cesium-contaminated soil using consecutive washing enhanced with electro-kinetic field

Purpose

Extensive deposition of Pb, As, and Cs in soils may damage ecosystems and human’s health. Soil washing is the most conventional remediation method, and its efficiency depends on metal solubility in soil. This study aims to optimize operating variables of electro-kinetic field (EKF)-enhanced soil washing procedures.

Materials and methods

Soil samples from a Mississippi River Delta rice field were homogeneously spiked with Pb, As, and Cs, and contaminated soil was aged for 3 months. The remediation involved a first stage electro-kinetic process, followed by a soil washing procedure. Soil pH changes under EKF were studied. Effects of citric acid and reversed EKF were investigated for alleviating possible alkaline precipitation. In the washing procedure, soil washing time and cycles with different extractants were examined. The overall EKF-enhanced soil washing efficiencies were discussed as well.

Results and discussion

The implement of EKF offered an acidic soil environment around the anode areas for solubilizing metal(loid)s. Combined with EKF, citric acid was more conductive to desorb metal(loid)s. In addition, the reversed EKF effectively alleviated metal(loid) precipitation caused by alkalization in the first stage cathode areas. The EKF significantly enhanced metal(loid) extractions in the anode area of soils using Na₂EDTA, CaCl₂, and citric acid at pH of 2. The most preferable removal of Pb (80–98 %), As (48–63 %), and Cs (10–13 %) was achieved with three extractants. CaCl₂ and citric acid were proved to be suitable alternatives to Na₂EDTA for Pb extraction. A washing process of 2 h extraction with double washing cycles was optimized.

Conclusions

Soil washing time and cycles were major factors governing the metal(loid) removal from soil. Washing process of 2 h extraction with double cycles was optimized for further extraction based on higher washing efficiency. The EKF effectively improved washing efficiency while some electrical parameters need further studies for cost performance consideration.

     

Hydraulic Structures in Water Aeration Processes

The primary purpose of water aeration is to increase the oxygen saturation of the water. This can be achieved by using hydraulic structures because of substantial air bubble entrainment at these structures. This paper reviewed the literature on hydraulic structures used in water aeration processes. The hydraulic structures were divided into two groups as the high-head flow systems and the free-surface flow systems. The high-head flow systems were circular and venturi nozzles, pipe with venturi tube, and high-head conduit, and the free-surface flow systems were weir, stepped cascade, and free-surface conduit. Air/water flow ratio and aeration efficiency in circular nozzles with air holes and venturi nozzles were significantly high. Pipes with venturi tubes showed high aeration efficiency although they had low air/water flow ratio. In high-head and free-surface conduits, almost full oxygen transfer, up to the saturation value, occurred. Forty-five degrees triangular sharp-crested weir had significantly better air/water flow ratio and aeration efficiency than other sharp-crested weir shapes. Stepped cascades, in particular nappe flow regime, were very efficient means of aeration.     

Antifungal and herbicidal properties of essential oils and n-hexane extracts of Achillea gypsicola Hub-Mor. and Achillea biebersteinii Afan. (Asteraceae)

The chemical composition of essential oils isolated by hydrodistillation from the aerial parts of Achillea gypsicola Hub-Mor., Achillea biebersteinii Afan. and n-hexane extracts obtained from the flowers of A. gypsicola and A. biebersteinii Afan. was analyzed by GC and GC–MS. Camphor (40.17–23.56%, respectively), 1,8-cineole (22.01–38.09%, respectively), piperitone (11.29–0.37%, respectively), borneol (9.50–5.88%, respectively) and α-terpineol (1.56–5.15%, respectively) were found to be the main constituents in A. gypsicola and A. biebersteinii essential oils. Furthermore, hexane extracts of A. gypsicola and A. biebersteinii consist of mainly camphor (37.78–27.88%, respectively), 1,8-cineole (13.43–24.78%, respectively), piperitone (15.57%-tr, respectively), n-eicosane (1.61–9.68%, respectively), n-heneicosane (2.56–9.55%, respectively), n-tricosane (3.46–10.04%, respectively), linoleic acid (6.19–3.17%, respectively) and borneol (5.66–5.58%, respectively). Although the oils and extracts were characterized relatively by high content of oxygenated monoterpenes, hexane extracts of the plant samples relatively rich in n-alkanes, fatty acids and fatty acid esters as compared with the oil. The oils and hexane extracts were also tested against 12 phytopathogenic fungi and the oils found to be more toxic as compared with hexane extracts of the plant samples. A. gypsicola oil only did not inhibit the growth of Fusarium graminearum. The extracts also strongly increased the growth of Fusarium equiseti and F. graminearum. Therefore, the antifungal activity of the oils can be attributed to their relatively high content of oxygenated monoterpenes. The results of herbicidal assays of the essential oils and hexane extracts of the plant samples against five important weeds in cultivated areas, Amaranthus retroflexus L., Chenopodium album L., Cirsium arvense L. (Scop.), Lactuca serriola L. and Rumex crispus L. showed that, in particular, the oils had inhibitory effects on the seed germination and seedling growth of A. retroflexus, C. arvense and L. serriola. The hexane extracts also showed lower herbicidal effect against the weeds in comparison to that of the oils. The findings of the present study suggest that the essential oils have a potential to be used as herbicide as well as fungicide.     

Integrating pine honeydew honey production into forest management optimization

Pine honeydew honey is an economically important non-wood forest product from eastern Mediterranean Pinus brutia forests, which are also important for timber production. Pine honey is produced by bees that feed on the honeydew secretions of Marchalina hellenica, a scale insect that infests pine stands and feeds on pine sap. The aim of this study was to optimize the joint production of pine honeydew honey and timber by maximizing the soil expectation value of pine stands. The simulation of P. brutia stand dynamics and timber production in healthy and infested stands is based on individual-tree growth and yield models that account for the effect of M. hellenica on tree- and stand-level growth and mortality. The optimization procedure uses a direct search method based on nonlinear programming. The results suggest that pine stands growing on good sites should be managed using rather short rotations and mainly aiming at timber production. In contrast, forest management in medium- and poor-quality sites should aim at longer rotations by taking advantage of the joint production of pine honey and timber assortments. Honey-oriented forest management can be much more profitable than timber production in stands growing on medium and poor sites. Pine honey represents an opportunity to increase the value and economic profitability of P. brutia forests.