Genetic variation in farmed populations of the gilthead sea bream Sparus aurata in Greece using microsatellite DNA markers

Genetic variation in seven reared stocks of gilthead sea bream Sparus aurata, originating from Greek commercial farms, was assessed using five polymorphic microsatellite markers and was compared with that of two natural populations from the Ionian and the Adriatic Seas. The total number of alleles per marker ranged from 11 to 19 alleles, and hatchery samples showed the same levels of observed heterozygosity with samples from the wild but substantially smaller allelic diversity and expected heterozygosity. The global genetic differentiation for the cultivated samples was significant as indicated by F_st analysis, which might indicate random genetic drift and inbreeding events operating in the hatcheries. On the contrary, no significant difference was found between the two wild populations. Population pairwise tests between farmed and wild stocks were also significant, with the exception of one hatchery sample, the Central Greece 1, which was not significantly different from the two wild samples perhaps due to its recent use in aquaculture from wild‐caught animals. The UPGMA tree topology grouped the wild samples together with the Central Greece 1 stock, and showed a clear division between wild and farmed sample sets for the six remaining hatchery samples. Knowledge of the genetic variation in S. aurata cultured populations compared with that in the wild ones is essential for setting up appropriate guidelines for the proper monitoring and management of the stocks either under traditional practices or for the implementation of selective breeding programmes.     

Agronomic techniques to controlLobesia botrana

The grapevine mothLobesia botrana (Denis & Schiffermüller) (Lepidoptera: Tortricidae) is a key pest of grapevines in Greece. As part of a broader study on integrated pest management, the effects were investigated of different cultural methods on the establishment and survival ofL. botrana, specifically: application of different nitrogen levels (30 and 100 units of ammonium sulfate or 70 units of Agrobiosol); summer leaf and shoot pruning; application of growth regulators (Regalis, prohexadione-calcium; or Falgro, gibberellic acid). There were significant differences among the three levels of N application. The lowestL. botrana infestation rates were found in plots treated with 30 units of (NH₄)₂SO₄ and plots that received some summer pruning. Following the application of plant growth regulators, the lowestL. botrana infestation levels occurred in the plots treated with Regalis or Falgro at the manufacturers’ recommended concentrations. On vines where growth regulators had been applied, the clusters had fewer berries than those not treated with growth regulators. http://www.phytoparasitica.org posting June 11, 2008.     

Discrete roles of a microsomal linoleate desaturase gene in olive identified by spatiotemporal transcriptional analysis

The relative abundance of alpha-linolenic (alpha-LeA) compared with linoleic acid is associated with the developmental stage and the plant species and is proposed to have important physiological effects on both vegetative and reproductive plant development. The enzymes responsible for catalyzing the conversion of linoleic acid to alpha-LeA, the omega-3 fatty acid desaturases (FADs), are localized in the plastid or the endoplasmic reticulum (ER). Here we present the isolation of an ER-type omega-3 FAD gene (OeFAD3) from olive (Olea europaea L.). Expression patterns of OeFAD3 in different seed tissues and mesocarps during olive fruit development showed that its contribution to olive oil biosynthesis and modification is minimal. Regulation of OeFAD3 differed from that of its plastidial counterpart, being preferentially expressed in proliferating tissues, in concert with the active membrane biogenesis required for cell division. Trienoic acid-deficient Arabidopsis mutants are male sterile, because alpha-LeA-derived jasmonic acid (JA) is required for pollen development. However, the upregulation of OeFAD3 in different pistil tissues, particularly in vascular bundles and ovaries, rather than in anthers, implies a critical role of alpha-LeA in female gametophyte development in olive, corroborating results from JA-defective tomato mutants that are female sterile but not male sterile.     

Common carp (<Emphasis Type="Italic">Cyprinus carpio</Emphasis>) response to two pieces of music (“Eine Kleine Nachtmusik” and “Romanza”) combined with light intensity,using recirculating water system

The objective of this study was to further investigate the effects of music on fish physiology, bearing in mind available information regarding the involvement of endogenous and exogenous factors in fish farming. Therefore, Cyprinus carpio (50.5 ± 0.36 g) were reared in a recirculating water system under 80 and 200 lux and subjected to no music at all (control, ambient noise only), 4 h of Mozart’s “Eine Kleine Nachtmusik”, or 4 h of anonymous “Romanza-Jeux Interdits” for 106 days. Both music treatments resulted in increased growth performance at both light intensities, with Romanza treatment at 200 lux resulting in better growth performance than Mozart treatment. Furthermore, feed efficiency for the Romanza groups was significantly better than for the control. Although no significant music effect was apparent for brain neurotransmitters, lower anterior intestine alkaline protease levels were detected for both music treatments. Taking into consideration the numerous advantages of recirculating water systems, it should be emphasised that fish response to music expresses the results of various physiological and biochemical processes, especially when fish notably respond differently when subjected to two different pieces of music.     

Ontogeny of the shi drum Umbrina cirrosa (Linnaeus 1758), a candidate new species for aquaculture

The ontogeny of shi drum Umbrina cirrosa (Linnaeus 1758), a candidate new species for aquaculture, was studied throughout the entire larval phase. Geometric morphometric analysis revealed two clear inflection points (7.0 and 12.7 mm total length, TL) in the shape ontogeny of this species, separating the studied period into three phases of different allometric priorities. Spline graphs demonstrated that the major non‐uniform shape ontogeny correlated with the development of the fins, the anterior dorsal area of the body, the caudal peduncle, the eye and the mouth. Concerning the morphological features, shi drum larvae are characterized by an upward anterior bending of the notochord. The ontogeny of the fins began with the formation of the pectoral buds (2.9 mm TL), continued with the notochord flexion (4.3 mm TL, associated with the caudal fin development), the appearance of the pelvic buds, the first anal rays (4.5 mm TL) and the first dorsal rays (4.8 mm TL). Shi drum juveniles presented 25 vertebrae and the following dominant fin types: D XI,23, AII,6, VI,5, P17 and C17.     

A critical assessment on arsenic partitioning in mine-affected soils by using two sequential extraction protocols

The highly degraded mine-affected soils of Lavrion, central Greece, are greatly polluted by heavy metals and arsenic (As). To assess As partitioning in the soils of the area, Wenzel and BCR (Community Bureau of Reference) sequential extraction procedures (SEP) were applied to 29 top soils. The results of the Wenzel SEP showed that As was mainly bound to the well-crystallized (33.3%) and to the amorphous/poorly-crystalline (30.1%) oxides of Fe, Al, and Mn. According to the BCR scheme, most of the total As (78.4%) was retained in the residual phase. Low mobility factor values (Wenzel: 0.34%; BCR: 1.56%) clearly demonstrate the low availability and mobility of As in the studied soils. The specifically-sorbed/inner-sphere and the reducible fractions of As, obtained by the Wenzel SEP, were positively correlated with clay and Fe oxides content, respectively. The reducible As fractions of both SEPs were negatively correlated with carbonates content indicating that carbonates may partially control As sorption on Fe oxides. The comparative evaluation of the two SEPs showed that the application of the BCR protocol in contaminated soils cannot provide reliable information on As sequestration in soils but it can be a first estimate of As labile forms.     

Isolated metal atom geometries as a strategy for selective heterogeneous hydrogenations

Facile dissociation of reactants and weak binding of intermediates are key requirements for efficient and selective catalysis. However, these two variables are intimately linked in a way that does not generally allow the optimization of both properties simultaneously. By using desorption measurements in combination with high-resolution scanning tunneling microscopy, we show that individual, isolated Pd atoms in a Cu surface substantially lower the energy barrier to both hydrogen uptake on and subsequent desorption from the Cu metal surface. This facile hydrogen dissociation at Pd atom sites and weak binding to Cu allow for very selective hydrogenation of styrene and acetylene as compared with pure Cu or Pd metal alone.     

Effects of climate and site characteristics on Scots pine growth

Scots pine is a highly diverse species, extended across Europe from Scandinavia to Spain, Italy, Greece and Turkey. It is also a valuable species, used in many commercial monoculture plantations in Great Britain and particularly in Scotland. Because of the diversity of growing environments and its commercial importance, it is necessary to identify the combination of significant factors affecting the observed variability of growth. Temperature, mainly during the growing season, is quite commonly considered as the most important factor in knowledge-based or empirical models. However, in highly oceanic climates like that of Scotland, the impact of temperature may have a less significant impact on growth. Here we argue that other factors, such as incoming winter solar radiation, frost, drought and management also have a significant effect on the growth of Scots pine. In addition, we argue that the already developed Ecological Site Classification knowledge-based model, used as a forest management tool in Great Britain, should be updated to incorporate our findings. Furthermore, we discuss the need to include management impact and possibly more physiological based components in its growth modelling routines, as these would allow the introduction of the effect of winter solar radiation.     

Effect of citric acid and glycine addition on acrylamide and flavor in a potato model system

Acrylamide levels in cooked/processed food can be reduced by treatment with citric acid or glycine. In a potato model system cooked at 180 degrees C for 10-60 min, these treatments affected the volatile profiles. Strecker aldehydes and alkylpyrazines, key flavor compounds of cooked potato, were monitored. Citric acid limited the generation of volatiles, particularly the alkylpyrazines. Glycine increased the total volatile yield by promoting the formation of certain alkylpyrazines, namely, 2,3-dimethylpyrazine, trimethylpyrazine, 2-ethyl-3,5-dimethylpyrazine, tetramethylpyrazine, and 2,5-diethyl-3-methylpyrazine. However, the formation of other pyrazines and Strecker aldehydes was suppressed. It was proposed that the opposing effects of these treatments on total volatile yield may be used to best advantage by employing a combined treatment at lower concentrations, especially as both treatments were found to have an additive effect in reducing acrylamide. This would minimize the impact on flavor but still achieve the desired reduction in acrylamide levels.