Diversity maintenance and use of Vicia faba L. genetic resources

The faba bean (Vicia faba L.) is an ancient crop that is represented in collections by cultivated forms only. Botanic and molecular data suggest that the wild ancestor of this species has not yet been discovered or has become extinct. This fact makes ex situ collections more crucial for the present and future breeding activities of this crop, especially when the modernization of agriculture reduces genetic diversity.     

Atypical Reactive Center Kunitz-Type Inhibitor from the Sea Anemone Heteractis crispa

The primary structure of a new Kunitz-type protease inhibitor InhVJ from the sea anemone Heteractis crispa (Radianthus macrodactylus) was determined by protein sequencing and cDNA cloning. InhVJ amino acid sequence was shown to share high sequence identity (up to 98%) with the other known Kunitz-type sea anemones sequences. It was determined that the P1 Thr at the reactive site resulted in a decrease of the K(i) of InhVJ to trypsin and α-chymotrypsin (7.38 × 10(-8) M and 9.93 × 10(-7) M, respectively). By structure modeling the functional importance of amino acids at the reactive site as well as at the weak contact site were determined. The significant role of Glu45 for the orientation and stabilization of the InhVJ-trypsin complex was elucidated. We can suggest that there has been an adaptive evolution of the P1 residue at the inhibitor reactive site providing specialization or functional diversification of the paralogs. The appearance of a key so-called P1 Thr residue instead of Lys might lead to refinement of inhibitor specificity in the direction of subfamilies of serine proteases. The absence of Kv channel and TRPV1-receptor modulation activity was confirmed by electrophysiological screening tests.     

Understorey fuel load estimation along two post-fire chronosequences of Pinus halepensis Mill. forests in Central Greece

Pinus halepensis forests are among the forest ecosystems in the Mediterranean Basin most affected by fire. Their distribution across lowland areas, in particular along the wildland–urban interface, increases the need to understand their ecology and responses to fire regime for their effective management. Apart from the extremely flammable tree layer, in several stands of these forests there is an increased fuel load attributed to the well-developed understorey of evergreen sclerophyllous shrubs. Taking into consideration that, in contrast with the long period required for full development of post-fire-regenerating pines, these shrubs resprout vigorously within the first post-fire weeks, it is important to explore the temporal trend of fuel accumulation to determine the risk of a second fire across a burned landscape. Two post-fire chronosequences of, in total, 12 P. halepensis stands were considered for sampling in Central Greece. The first chronosequence corresponds to pine stands characterized by the dominance of evergreen sclerophyllous shrubs in the understorey (Type 1) whereas the second chronosequence corresponds to pine stands where the cover of such shrubs was lower (Type 2). This study helps in understanding the fuel dynamics according to the type of P. halepensis forest stand and to anticipate future biomass growth. The proposed equations are simple tools, enabling land managers to estimate understorey total fuel load easily by visually recording the cover and height of the evergreen sclerophyllous shrub component, to justify understorey fuel reduction measures.     

Effect of common bean (Phaseolus vulgaris L.) on the community composition of ammonia-oxidizing bacteria in soil previously cultivated with Medicago sativa

The community composition of ammonia-oxidizing bacteria (AOB) was studied during four stages of plant development in soil cultivated with Phaseolus vulgaris in comparison to unplanted soil, using an alfisol previously harboring the legume Medicago sativa. Denaturing gradient gel electrophoresis (DGGE) patterns of 16S rRNA gene and clone libraries of the same gene suggested that bacteria related to Nitrosospira cluster 3 were dominant in both planted and unplanted soil. Bacteria related to Nitrosomonas cluster 8 (Nitrosomonas communis cluster) were found at all times in planted soil, but appeared only randomly in unplanted soil. Analysis of PCR products of the gene encoding the alpha-subunit of ammonia monooxygenase (amoA) by DGGE and clone libraries only detected Nitrosospira cluster 3-like organisms, but failed to detect sequences related to Nitrosomonas. The results suggest that P. vulgaris does not affect the dominant members of AOB communities (Nitrosospira cluster 3), but could have an effect on the prevalence of Nitrosomonas cluster 8 in this type of legume-planted alfisol.     

Methodological alternatives for calculation of enrichment factors used for assessment of topsoil contamination

Purpose

The research is aimed at comparison of different enrichment factors (EFs) calculated for potentially harmful chemical elements (PHEs) basing on topsoil data from Klaip?da with geological differences between two areas, choice of the reference elements (REs), consideration of the expediency and efficiency of normalisation, the influence of PHE and RE background or upper threshold values on the estimated contamination level of 50 schoolyards and the arising problems, i.e. which PHE should be normalised.

Materials and methods

Composite topsoil samples taken in 50 schoolyards and 28 football fields from 0 to 10-cm depth were air-dried, sieved to <1 mm, milled and analysed for total contents of major elements and As, Ba, Cr, Cu, Mn, Mo, Ni, Pb, Sn, U, V and Zn by energy-dispersive X-ray fluorescence and of Ag and Co by optical atomic emission spectrophotometry. Simple EFs in schoolyards were calculated normalising by concentration factor (CF) of Fe, while complex EFs normalising by weighted average of Al, K and Ti concentration factors (WACFs).

Results and discussion

The variability of RE is shown with significant differences between sandy western and loamy eastern areas and lower differences between schoolyards and football fields. The highest effectiveness of normalisation, i.e. the number of sites where WACF > 1 or CF > 1, is when RE background values for schoolyards differentiated for each area are selected. The formulas for the ratio of different EFs demonstrate that (1) for Co, Ba, Mn, Mo, Pb and Cu, the upper threshold-type EFs exceed the background-type EFs; (2) there is the tendency to obtain lower EFs for the greater part of PHE when using differentiated background of PHE and RE. The problems of estimation of the background of some PHE and the expediency of their normalisation are discussed.

Conclusions

The recommendations are (1) to explore the variability of RE in the urban territory and to find out if there are areas with significant differences in RE content, in this case try to estimate the differentiated background values of RE and PHE, because respective EFs are usually lower; (2) for more effective normalisation, to use background values of RE which correspond to the object of assessment; (3) not to use upper threshold-type EFs; (4) to be careful with interpretation of EFs for those PHEs which have significant negative correlation with RE.

     

An Improved Gravimetric Method to Determine Total Petroleum Hydrocarbons in Contaminated Soils

A gravimetric method to determine heavy fractions of total petroleum hydrocarbons (TPH) in soils is reported. The method was adapted and calibrated by modifying previous standard methods published, incorporating energy and cost savings where possible. Artificially contaminated soils with different organic matter content, and aged in stationary mode for a period of 8 months were used for calibration. Insufficient solvent evaporation was identified as the most prevalent and largest positive interference in the gravimetric detection. To overcome this, while minimizing the need for heating, a combination of three 10-min rotary evaporator steps and 30 min of vacuum in a desiccator were applied, for a total solvent volume of 60 ml. Hexane was chosen as the extraction solvent and a 40–60 min treatment in an ultrasound bath of 260 W was found suitable to extract 80–95% of TPH extracted by the Soxhlet method. Finally, the use of silica gel for cleanup of co-extracted natural organic matter was found unnecessary, because of the low amounts co-extracted for soils with up to 5% organic carbon, and because the chemical nature of the co-extracted organic matter prevents its selective adsorption to silica.     

Effects of biosolarization as methyl bromide alternative for <Emphasis Type="Italic">Meloidogyne incognita</Emphasis> control on quality of soil under pepper

The Adenosine triphosphate (ATP) content, dehydrogenase, phosphatase, urease, and β-glucosidase activity decreased after manure amendment plus solarization (biosolarization), but they recovered after cropping, reaching levels higher than or similar to those before the biosolarization. However, these biochemical parameters decreased and did not recover with time in the methyl bromide (MeBr) treatment. Potential negative soil effects were assayed by measuring, ecotoxicity (Vibrio fisheri luminescence), germination index, electrical conductivity, and heavy metals content. Biosolarization did not negatively affect these parameters, while MeBr application irreversibly decreased the germination index and ecotoxicity. Higher-quality pepper production (extra and first class) were observed with biosolarization but not with MeBr, but no differences were found for pepper yield. Biosolarization gave a Meloidogyne incognita (M. incognita) incidence similar to that of MeBr application.     

Landscape changes influence the reproductive behaviour of a key ‘capital breeder’ snake (Boa constrictor occidentalis) in the Gran Chaco region, Argentina

Many wild reptile species are threatened by habitat loss. However, the way in which changes in landscape patterns influence intraspecific ecological processes is not completely understood. Boa constrictor occidentalis is an endangered species and has a special conservation value since it is endemic of dry forests in the Gran Chaco region. Because the Gran Chaco is largely threatened due to habitat loss it is necessary to know how landscape changes influence this species. Therefore, we evaluated the effects of forest loss and landscape composition on the reproductive life-history parameters. Landscape changes were assessed by analyzing satellite imagery and reproductive parameters were determined by ultrasound images of the reproductive structures. The obtained results indicate that habitat loss may affect body condition, clutch size and testicular volume of the Argentine boa constrictor. We also found that the spatial pattern of vegetation influences the distribution of females and males in the landscape. Matting aggregations are scarce in shrublands. Therefore, our study shows that forest loss could enhance vulnerability to extirpation through constraints placed on reproduction. We encourage resource managers to evaluate sensitive reproductive life-history parameters as well as habitat deterioration to asses the conservation status of the populations of the Argentine boa constrictor. Since the Gran Chaco forest, a key habitat to the species’ reproduction, is largely threatened, strong conservation action is needed to halt and reverse forest loss in this region.     

Posterotestes unelen gen. et sp. n. (Digenea: Apocreadiidae) from Percichthys trucha (Osteichthyes: Percichthyidae) in Patagonia, Argentina

Posterotestes gen. n. (Digenea: Apocreadiidae, Apocrcadiinae) is proposed for specimens with the following features: spiny body, posterior position of gonads, extension of vitelline follicles up to level of intestinal bifurcation and absent at post-testicular space, long oesophagus and extension of caeca up to anterior testis. Posterotestes unelen sp. n. is described from the intestine of the native fish, Percichthys trucha (Cuvier et Valenciennes) (Osteichthyes: Percichthyidae) from Patagonian Andean lakes.