Glycoalkaloids are secondary metabolites commonly found in Solanaceae plants. They have anti-bacterial, anti-fungal and insecticidal activities. In the present study we examine the effects of potato and tomato leaf extracts and their main components, the glycoalkaloids α-solanine, α-chaconine and α-tomatine, on development and reproduction of Drosophila melanogaster wild-type flies at different stages. Parental generation was exposed to five different concentrations of tested substances. The effects were examined also on the next, non-exposed generation. In the first (exposed) generation, addition of each extract reduced the number of organisms reaching the pupal and imaginal stages. Parent insects exposed to extracts and metabolites individually applied showed faster development. However, the effect was weaker in case of single metabolites than in case of exposure to extracts. An increase of developmental rate was also observed in the next, non-exposed generation. The imagoes of both generations exposed to extracts and pure metabolites showed some anomalies in body size and malformations, such as deformed wings and abdomens, smaller black abdominal zone. Our results further support the current idea that Solanaceae can be an impressive source of molecules, which could efficaciously be used in crop protection, as natural extract or in formulation of single pure metabolites in sustainable agriculture.

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DNA barcoding is a standard and efficient method, frequently used for identification, discrimination and discovery of new species. Although this approach is very useful for classifying the world's biodiversity, little is known about its usefulness in barcoding at lower taxonomic level and its discrimination rate for closely related species, like conifers. In this study, we compared the genetic variation of eight chloroplast DNA barcode regions (matK, rbcL, trnH-psbA, trnL-trnF, rpl20-rps18, trnV, ycf1, ycf2) in 17 conifers - three closely related pines from Pinus mugo complex and 14 more distant conifers representing two genera and four sections of the Pinaceae family. The discrimination rate for a single and for multiple DNA barcode regions analyzed in this study was estimated using the Tree-Building and PWG-Distance methods. The usefulness of the DNA barcoding approach for analyzing and resolving taxonomic inconsistency among closely related and more phylogenetically distant conifers was evaluated and discussed.

Bryophytes are amongst the most ancestral terrestrial plants and often have large distribution ranges across continents. Recent biochemical and molecular studies have suggested that many worldwide morphological species of bryophyte may represent genetically divergent and reproductively isolated cryptic species. We tested the cryptic species hypothesis in the thalloid liverwort Aneura pinguis complex. We applied analyses of chloroplast DNA (cpDNA) sequence variation and polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) methods to discriminate between specimens of A. pinguis derived from various habitats in five distant geographical regions in Poland. Of the 19 specimens sequence characterized for the cpDNA tRNALeu region, seven haplotypes were identified divided into three nonmonophyletic clusters. The application of developed PCR‐RFLP markers confirmed the existence of three tRNALeu types of A. pinguis (A–C) within the specimens derived from 21 populations. Sympatric populations of different tRNALeu types were found in lowland and mountain regions. No clear correlation between stand type and the presence of two tRNALeu types (A, B) was observed, as both were growing on soil, humus, and rocks. The tRNALeu type C was found only on humus and its distribution was restricted to low‐lying northern populations. The above results indicate that the A. pinguis complex is highly differentiated at the molecular level and may represent three cryptic species. © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society, 2007, 155, 273–282.

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This isoenzymatic and cytogenetic study has shown significant differences in genetic composition between two groups of Pinus sylvestris trees: tolerant and sensitive to heavy metal pollution. Total and mean numbers of alleles and genotypes per locus were higher in the pollution-sensitive group of trees, but heterozygosity (Ho) was lower in this group. Fixation index (F) indicates that trees tolerant for pollution were in the Hardy-Weinberg equilibrium, while the sensitive group had a significant excess of homozygosity. Cytological analyses demonstrated numerous aberrations of chromosomes in meristematic root tissue of seedlings developed from seeds collected from trees in the polluted area. The aberrations included chromosome bridges and stickiness, laggards, retarded and forward chromosomes, and their fragments. The mitotic index was markedly lower in this group of seedlings, as compared to the control. Both isoenzymatic and cytological analyses showed a significant influence of heavy metal ions on the genetic structure of the Pinus sylvestris population.

Ab~ra~Isozyme markers were used to investigate the origin of the polyploid liverwort, Pellia borealis (gametophytic n -18), which was believed to represent an autopolyploid form of Pellia epiphylla (n -9). Enzyme variation was studied in four taxa: polyploid P. borealis, two recently discovered sibling species of P. epiphylla complex, and the closely related P. neesiana (n -9). (3ametophytes of the polyploid showed a complex electrophoretic phenotype for three diagnostic enzymes (DIAl, MPI1 and ACO) in contrast to simple pattern in all haploid taxa. It was postulated that the pattern found in the polyploid represents a 'fixed heterozygons' phenotype resulting from aUopolyploidy. Alleles present in the polyploid were found (with only one exception) in the two sibling species of the P epiphylla complex, suggesting that they are the parents of the allopolyploid. Pellia neesiana was excluded as a donor of either of the genomes. Variation in the polyploid suggests at least three separate origins of P. borealis.

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