Molecular evidence for allopolyploid speciation and a single origin of the western Mediterranean orchid Dactylorhiza insularis (Orchidaceae)

The hybrid origin of the western Mediterranean orchid Dactylorhiza insularis was demonstrated by genetic markers. Allozyme data showed that throughout its range D. insularis has an allotriploid constitution and reproduces apomictically. The parental species of D. insularis were identified as D. romana andD. sambucina; they contributed 2 alleles and 1 allele, respectively, at the allozyme loci studied. The maternal species of D. insularis was D. romana , as inferred from cpDNA ( trn L(UAA) intron). High genetic similarities were found when comparing present populations of D. romana and D. sambucina with their respective genomes 'frozen' in D. insularis. Dactylorhiza insularis showed fixed (or nearly fixed) heterozygosity at 11 out of the 19 loci studied, and poor genetic variation: eight multilocus genotypes were detected at allozyme level. No multilocus genotype differs from the most similar one by more than one allele substitution. All D. insularis individuals showed the same cpDNA haplotype (I) , regardless of their geographic origin and multilocus genotype. The I haplotype is similar, but not identical to that found in D. romana (R). No recurrent formation of D. insularis was observed in hybrid zones between D. romana and D. sambucina , where diploid sexual hybrids (F_1; F_n, backcrosses) were detected. Available data agree with a single origin for D. insularis , which possibly occurred in the present postglacial, when D. romana and D. sambucina , expanding from their glacial refugia, came into contact. The genetic homogeneity found between D. romana and D. markusii , both from their locus classicus , indicates that the latter is a junior synonym of D. romana; on the other hand, D. romana and D. sambucina are well differentiated species ( D_Nei = 0.59).     

Nature protection areas of Europe are insufficient to preserve the threatened beetle Rosalia alpina (Coleoptera: Cerambycidae): evidence from species distribution models and conservation gap analysis

1. Natura 2000 network (N2000) and national protected areas (NPAs) are recognised as the most important core ‘units’ for biological conservation in Europe. 2. Species distribution models (SDMs) were developed to detect the potential distribution of the rare and threatened cerambycid beetle Rosalia alpina L. in Europe, and the amount of suitable habitat within the N2000 network [special areas of conservation (SACs) and special protection areas (SPAs)], NPAs (e.g. national parks, regional parks, state reserves, natural monuments and protected landscapes) and the overall European protected area network (EPAN) (N2000 + NPAs) was quantified. 3. According to this analysis, the suitable habitat for R. alpina in Europe amounts to c. 754 171 km² and stretches across substantially uninterrupted areas from Portugal to Romania (west to east) and from Greece to Germany (south to north). The overlay between the existing system of conservation areas in Europe (N2000 and NPAs) and the binary map for R. alpina showed that only c. 42% of potential habitat is protected. SACs and SPAs protect c. 25% and 21% of potential habitat, respectively. However, because the two site types often spatially overlap, when taken together the entire N2000 network protects c. 31% of potential habitat. Instead, NPAs offer a degree of protection of c. 29%. Overall, almost 60% of the area potentially suitable for the species is unprotected by the EPAN, an aspect that should be considered carefully when planning the conservation of this beetle at a large scale. 4. These results may also help to focus field surveys in selected areas where greater chances of success are encountered to save resources and increase survey effectiveness.     

Serological potential for fungal identification

POLONELLI, L. & MORACE, G., 1989. Serological potential for fungal identification. Specific antigens are valuable for the identification of fungal cultures. Early attempts to immunoidentify fungi were hampered by heterogeneity of antigens, antibody preparations and use of improper serological procedures. In recent years, the double diffusion exoantigcn technique has proved to be the most effective method for immunological identification of mycelial fungus cultures. Additional advances in perfecting methods occurred with the adoption of improved reference antisera obtained either through absorption or by immunizing animals with selected immunoelectrophoretic arcs or precipitin bands (reference antigens). Preliminary studies have shown that serodiagnostically important antigens may be used for accurately and rapidly identifying hyaline as well as dematiaceous fungi. Agglutination techniques consisting oflatex particles sensitized with rabbit anti- Cryptococcus neoformans globulin or Candida monospecific antisera permit the detection of specific yeast antigens in a few minutes. In spite of the great success obtained with the antigen test methods, some limitations in these procedures are apparent. The major problem derives from the occurrence of extensive cross reactions among congeneric species.
Hybridoma technology permits the production of uniform and standardized antisera (monoclonal antibodies) reacting with species-specific or strain-specific antigenic determinants (Western blotting technique) and the availability of functional pure epitopes (affinity chromatography). The current value and limitations as well as further avenues for the advance of the different procedures are reported.     

Rimsulfuron in soil: Effect of persistence on growth and activity of microbial biomass at varying environmental conditions

The research was carried out toascertain the effect of rimsulfuron, a solfonylureaherbicide, on soil microbial biomass growth andactivity. Laboratory experiments were performed in asilty clay loam soil to relate changes of soilmicrobial biomass-C content and global hydrolyticactivity to the rimsulfuron persistence underdifferent conditions of temperature and soil humidity.The results showed that rimsulfuron persistencedepended significantly on temperature, while itremained almost unchanged by humidity changes. A rangeof half-life values from 3.5 to 14.8 days was found ina temperature range from 10 °C to 25 °C,with lower half-lives at higher temperature.Persistence data were processed with the VARLEACHmodel, in order to predict rimsulfuron persistenceunder different environmental conditions. On comparingtreated soils with untreated soil samples, decreasesin the microbial biomass-C content and increases inthe global hydrolytic activity were found to beconnected with rimsulfuron persistence at the variousexperimental conditions. These effects persisted fora short time and, they were evident earlier at highertemperature and more persistent at lower humidity.This behaviour is discussed in terms of rimsulfurontoxicity, with the consequent release of endocellularhydrolytic enzymes from the dead microorganisms. Anequation was derived to calculate the microbialbiomass-C content in response to the variation ofrimsulfuron persistence.