Supplemental iodine as a key to reproduction in pandas?

Pandas are endemic to iodine-poor environments and appear to be specialized for a goitrogenic staple diet. In particular, the importance of thiocyanate in bamboos might possibly have been overlooked in captive breeding programs. Although excreted in urine, thiocyanate first antagonizes absorption of iodine by the thyroid (of parent, fetus and suckling juveniles) and the mammary glands. In livestock and humans, subclinical deficiency of iodine is known to result in reproductive problems (including retardation of the fetus and suckling infant) even where the mother appears to be unaffected beyond slight hyperplasia of the thyroid and subtle hypothyroidism as reflected by levels of thyroid hormones. We suggest that the possibilities of iodine deficiency or excess should be carefully considered wherever the reproductive rates of pandas are unsatisfactory.     

Economically profitable post fire restoration with black truffle (Tuber melanosporum) producing plantations

Cultivating black truffle (Tuber melanosporum Vittad.) is highly profitable in sites suitable for its development. Land use history is an important factor when choosing suitable habitat, and lands with non-ectomycorrhizal host species are recommended when introducing T. melanosporum-inoculated seedlings in order to reduce competition from native, soil-borne ectomycorrhizal (ECM) inoculum. Nearly every year Mediterranean wildfires cause the loss of forested lands where soil and climatic characteristics are suitable for truffle cultivation. Introducing T. melanosporum-inoculated seedlings in these sites could promote reforestation with a native ECM fungus and, in addition, may provide economic incentives. We tested the viability of burnt forest lands for truffle cultivation by introducing T. melanosporum-inoculated Quercus ilex seedlings in burnt forest sites with and without resprouting forest species which act as repositories for native ECM fungi. We also evaluated the role of the ECM host plants, which resprout after a forest fire, in the maintenance and dynamic processes of the ECM fungal community. The study followed a factorial design with two levels: (1) T. melanosporum-inoculated and non-inoculated Q. ilex seedlings and (2) presence and absence of ECM host plants resprouting after the fire. We established 10 experimental plots with 360 holm oaks. After four and a half years, the truffle-inoculated holm oaks maintained 36?% of their root tips colonized with T. melanosporum, and 10?years after plantations, 26.2?% of the surviving inoculated holm oaks displayed a “truffle burn” area. A greater ECM morphotype richness was associated with seedlings planted in plots with the presence of ECM host plants, whereas the T. melanosporum mycorrhizal ratio was constant. These results suggest that reforestation with T. melanosporum-inoculated seedlings can be successful following forest fires and highlights the competitiveness of this fungus within the ECM community in these soils.     

Euparyphium albuferensis and Echinostoma friedi (Trematoda: Echinostomatidae): experimental cercarial transmission success in sympatric snail communities

Euparyphium albuferensis and Echinostoma friedi cercarial infectivity to four species of sympatric snails was examined under single- or multiple-choice laboratory conditions to show the level of parasite-snail host compatibility. Radix peregra, Lymnaeafuscus, Physella acuta and Gyraulus chinensis act as second intermediate hosts of both parasite species although different cercarial transmission success (CTS) was observed. In single-host experiments, R. peregra and P. acuta showed a high degree of compatibility with E. albuferensis, while only P. acuta in the case of E. friedi. In two-choice snail communities, a snail with high CTS increased the values of another with low compatibility, in both parasite species. In multiple-choice snail communities, high CTS of some hosts decreased, while low CTS of other hosts increased. The degree of parasite-host compatibility of each snail species could be determined by the presence of other snails in the community.     

Biochemical and histological changes in the liver tissue of rainbow trout (Oncorhynchus mykiss) exposed to sub-lethal concentrations of diazinon

The organophosphate insecticide diazinon is widely used to control pest in Iran. The purpose of the present study was to investigate the antioxidant and histopathological changes in the liver tissue of rainbow trout (Oncorhynchus mykiss) exposed to 0.1 and 0.2 mg/L of a commercial formula of diazinon for a period of 28 days. Antioxidant enzyme activities—catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase—were determined after 7, 14 and 28 days of exposure. Histopathological analyses were performed at the 28th day. All antioxidant enzymes were induced after 7 days of diazinon treatment in both concentrations of diazinon. Catalase and superoxide dismutase maintained elevated activities during all the treatment period. Glutathione peroxidase activity returned to the control values at the 14th day, decreasing to values below control at the 28th day in both diazinon concentrations. Glutathione reductase maintained increased activities at the 14th day in the 0.1 mg/L diazinon, decreasing to control values at the 28th day. In the 0.2 mg/L group, the activity returned to control values at the 14th and decreased below the control at the 28th day. Total antioxidant capacity of hepatocytes significantly decreased in fishes exposed to diazinon during all experimental periods. Hypertrophy of hepatocytes, vacuolization of cell cytoplasm and hepatocyte cloudy swelling were observed in the liver tissue of fish exposed to both concentrations of diazinon. The results showed that diazinon altered the activity of antioxidant enzymes and the cellular total antioxidant capacity inducing oxidative stress and cellular damage in hepatocytes evidenced by histopathological analysis.     

Dynamic regulation of larval fish self‐recruitment in a marine protected area

The factors that regulate the self‐recruitment of fish larvae were explored in Cabrera National Park (CNP), an insular Marine Protected Area (MPA) located off southern Mallorca (Western Mediterranean). Our study attributes the regulation of larval arrival to the MPA to a combination of retention by topographically generated circulation patterns around the island and shelf break frontal dynamics. Specifically, within the shelf, interaction of the wind‐induced oscillatory flow with the island was shown to generate ephemeral recirculation patterns that, over time, favor larval retention in the proximity of the MPA. According to our measurements, oscillatory flows produced by wind‐forced island‐trapped waves (ITWs) dominate the flow around CNP. ITW‐forced dispersion simulations were in agreement with the observed distributions of several typical fish species that breed in the CNP. A second regulator of environmental variability is the influence of boundary currents and open ocean mesoscale structures at the shelf break. These structures generate frontal zones that are comparatively more long‐lived than inner‐shelf circulation patterns, and they were shown to act as barriers to the offshore dispersion of coastal fish larval assemblages. Finally, inferences from larval size distributions around the MPA together with particle‐tracking model simulations suggested the relevance of behavioral processes for larval recruitment to the MPA. Based on these observations, the waters around the CNP can be viewed as a relatively stable system that allows breeding fish populations to rely on self‐recruitment for their long‐term persistence, independent of other source populations along the coast of Mallorca.     

Seasonal variability of cephalopod populations: a spatio‐temporal approach in the Western Mediterranean Sea

Cephalopod populations show wide temporal fluctuations in abundance, which have usually been investigated at inter‐annual scales related to environmental variability. However, cephalopods are also strongly linked to seasonal environmental fluctuations owing to their short life cycles and single seasonal breeding. Therefore, population abundance critically depends on the success of breeding and recruitment from the previous year and the optimization of resources in a narrow period of favorable conditions. This adaptation of population dynamics is paramount in marked oligotrophic systems, such as the western Mediterranean Sea. We used monthly landings per unit effort (LPUE) to explore the spatio‐temporal variability in seasonal patterns of three cephalopod species (Illex coindetii, Eledone cirrhosa and Octopus vulgaris). Common trends across the study area were characterized for each species. In all cases, seasonal patterns were geographically aggregated in relation to differences in local environment (i.e., primary production and surface hydro‐climatology). Variability in the mean seasonal pattern over time was also investigated under contrasting environmental or population regimes. The mean seasonal trend was more pronounced in regimes of high‐population densities, suggesting a density‐dependent control that can modify the strength of the environmental forcing in the seasonal patterns. Our study also evidences a spatial synchrony in the seasonal fluctuations of LPUEs. Scales of synchrony ranged from 70 to 200 km, indicating a patchy‐aggregated spatial pattern as a part of complex population structures in the western Mediterranean. Improving our understanding of seasonal dynamics of cephalopods across temporal and spatial scales may lead to improved forecasts and management strategies.     

Relationship between phenotypic and genetic diversity of parental genotypes and the specific combining ability and heterosis effects in wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)

The purpose of the study was to evaluate the relationship between the genetic distances (GD) and phenotypic distances (PD) of parents and the specific combining ability (SCA) and heterosis effects. The experiment comprised 18 parental genotypes of wheat (Triticum aestivum L.) and 76 F₂ hybrids, obtained after crossing in a line × tester scheme. Parents and hybrids were examined in a field experiment conducted in a block design with three replications. SCA as well as mid-parent heterosis effects were estimated for selected morphological and technological traits. PDs and GDs were investigated between pairs of parental genotypes. GD between parental genotypes was evaluated by using randomly amplified polymorphic DNA markers. Heterosis was observed in all hybrids, and protein content exhibited the highest heterosis among the seven examined traits. The relationship between PD and GD as well as the SCA and mid-parent heterosis effects were evaluated using correlation coefficient. The correlation between PD, SCA and heterosis were low and not significant for the examined traits, whereas the correlation between SCA, heterosis and GDs were significant for protein content and rheological properties. The results indicate that GDs between parents can be used to predict performance of hybrids for selected technological traits.     

Genetic variation for carbon isotope composition in Juglans regia L.: relationships with growth, phenology and climate of origin

? Among the traits of breeding interest for the common walnut tree Juglans regia L., characteristics such as timing of budbreak and leaf fall, water-use efficiency and growth performance are regarded as being of utmost relevance in Mediterranean conditions.

? The authors evaluated intraspecific variation in δ¹³C (carbon isotope composition, surrogate of intrinsic water-use efficiency, WUE_i) for 22 J. regia families grown in a progeny test under supplementary irrigation, and investigated whether such variation correlated with climatic indicators of native habitats. The genetic relationships between δ¹³C, growth and phenology were also assessed during two consecutive years.

? Overall, the most water-use-efficient families (i.e. with higher δ¹³C), which originated mainly from drought-prone provenance regions which have a high vapour pressure deficit and low rainfall, exhibited less height growth and smaller DBH. Using a stepwise regression procedure, δ¹³C was included as the main explanatory variable of genotypic variation in growth traits, together with growing season duration (for DBH in both years) and flushing (for height in 2007).

? It was concluded that WUE_i is largely unconnected to phenology effects in the explanation of growth performance for J. regia, therefore suggesting the opportunity of simultaneously selecting for low WUE_i and extended growing period to maximise productivity in non-water-limited environments.

     

Genotype-environment interaction of barley doubled haploids with regard to malting quality

The genotype-environment (GE) interaction of barley doubled haploid (DH) lines was studied in relation to some malting quality characters. DH lines were obtained, using the bulbosum method, from F₁ hybrids between the cultivars ‘Grit’ and ‘Havila’. Thirty DH lines, the parental forms, F₂ and F₃ hybrids of ‘Grit’בHavila’ and the standard cultivar ‘Rudzik’ were studied in a series of field experiments repeated at six environments. Malt protein content, Kolbach index, extract yield and malt fine-coarse difference were measured. The statistical analysis was performed using the computer program SERGEN. For protein content, it was found that most of the lines studied were stable, i.e. their GE interactions were not significant. Among the malt traits, phenotypic values of Kolbach index and fine-coarse difference were most dependent on environmental conditions. For Kolbach index, only one line was found to be stable, while for fine-coarse difference, all lines displayed interaction with the environment.