Natural Occurrence of Pepino mosaic virus in Lycopersicon Species in Central and Southern Peru

Pepino mosaic virus (PepMV), a potexvirus first described in 1980 from pepino ( Solanum muricatum ) plants cultivated in Peru, was isolated from diseased tomato plants in the Netherlands in 1999, and is now the cause of an emerging tomato disease in Europe. In a survey of central and southern Peru, 65 wild and four cultivated populations of Lycopersicon , as well as six populations of other species of Solanaceae , were tested for the presence of PepMV and six other viruses. Of the Lycopersicon population sampled, 23 (35.4%) reacted positively in double antibody sandwich (DAS)-enzyme-linked immunosorbent assay (ELISA) with antisera to PepMV. DAS-ELISA tests for PepMV of other solanaceous species were negative, except for one sample of pepino ( Solanum muricatum ). Mechanical inoculation of susceptible Lycopersicon esculentum cv. NE-1 plants with crude sap extracts of 20 of these samples confirmed that 15 of them (from the Departments of Apurimac, Arequipa and Moquegua) were infected with PepMV; these inoculated plants were also DAS-ELISA positive and, in most cases, developed symptoms. Thirteen of the infective extracts were obtained from plants of wild Lycopersicon species (three L. chilense , three L. chmielewskii , two L. parviflorum and five L. peruvianum ) and one each from the cultivated species L. esculentum and S. muricatum . The wild Lycopersicon species are newly reported natural hosts of PepMV. Tests for the other six viruses were negative, except that two samples contained Tomato mosaic virus . Thus, PepMV occurs in Lycopersicon species in central and southern Peru, even in isolated wild populations. These results indicate that the virus is not new to the region and has an efficient mechanism of natural transmission.     

Genetic Diversity and Phylogenetic Relationships in the Genus Lycopersicon (Tourn.) Mill. as Revealed by Inter-Simple Sequence Repeat (ISSR) Analysis

Inter-simple sequence repeat (ISSR) analysis was for the first time used to study the genetic diversity and phylogenetic relationships in 54 wild accessions and cultivars of the genus Lycopersicon. Analysis involved 14 ISSR primers homologous to microsatellite repeats and containing additional selective anchor nucleotides. In total, 318 ISSR fragments were amplified for the wild and cultivated tomato genomes. The interspecific polymorphism revealed with the ISSR primers was 95.6%. Species-specific ISSR fragments were detected for each tomato species. The highest number (more than 20) of species-specific fragments were obtained for L. esculentum sensu lato, although the intraspecific variation of ISSR patterns was low. UPGMA cluster analysis was used to construct a dendrogram and to estimate the genetic distances between the species of the genus Lycopersicon; between populations ofL. peruvianum, L. pimpinellifolium, and L. esculentum; and between tomato cultivars. The ISSR-based phylogeny was generally consistent with Lycopersicon taxonomy based on morphological and molecular evidence, suggesting the applicability of ISSR analysis for genotyping and phylogenetic studies in tomato.     

RAPD analysis of genome polymorphism in the family Lemnaceae

The multilocus RAPD analysis of intergeneric, inter-and intraspecific nuclear genome polymorphism was used for the first time to assess intergeneric, interspecific, and intraspecific polymorphism in Lemnaceae growing on the territory of Russia. The origin of the chosen accessions overlapped with the natural range of duckweeds in Russia. Seventy-five Lemnaceae accessions representing eight species (L. minor, L. gibba, L. turionifera, L. japonica, L. trisulca, L. aequinoctialis, S. polyrhiza, and L. punctata) from three genera (Lemna, Spirodela, and Landoltia), were analyzed. The highest variability levels were revealed in L. minor accessions (0.03–0.20). Species L. trisulca and S. polyrhiza were characterized by values of genetic distance 0.01–0.18 and 0.03–0.16, respectively. The lowest polymorphism levels were detected for L. turionifera (0.01–0.11). The dendrogram based on RAPD data showed that L. aequinoctialis was the most genetically distant species of the genus Lemna. Accessions of species L. turionifera and L. japonica, as well as L. minor and L. gibba, did not form separate species-specific subclusters; rather, they fell into clusters with L. japonica/L. turionifera and L. minor/L. gibba. Accessions of the genera Spirodela and Landoltia formed two separate clusters combined into one group.     

Taphonomy and compositional fidelity of Quaternary fossil assemblages of terrestrial gastropods from carbonate-rich environments of the Canary Islands

Quaternary aeolian deposits of the Canary Islands contain well‐preserved terrestrial gastropods, providing a suitable setting for assessing the taphonomy and compositional fidelity of their fossil record over ~13 kyr. Nine beds (12, 513 shells) have been analysed in terms of multivariate taphonomic and palaeoecological variables, taxonomic composition, and the stratigraphic and palaeontological context. Shells are affected by carbonate coatings, colour loss and fragmentation. Shell preservation is size‐specific: juveniles are less fragmented and show colour preservation more commonly than adults. In palaeosols, the adult shell density correlates negatively with the proportion of fragmented adults, negatively with the proportion of juveniles, and positively with the proportion of adults with coatings. High bioturbation intensity in palaeosols is associated with low shell fragmentation and high proportion of shells with coatings. These relationships imply that high adult density in palaeosols was driven by an increase in shell production rate (related to a decrease in predation rates on adults and a decrease in juvenile mortality) and a decrease in shell destruction rate (related to an increase in durability enhanced by carbonate precipitation). In dunes, the relationships between taphonomic alteration, shell density and bioturbation are insignificant. However, dune assemblages are characterized by a lower frequency of shells with coatings and higher rates of colour loss, indicating lower shell durability in dunes than in palaeosols. Additionally, non‐random differences in the coating proportion among palaeosols imply substantial temporal variation in the rate of carbonate crust formation, reflecting long‐term changes in bioturbation intensity that covaries positively with shell preservation. Dunes and palaeosols do not differ in species abundances despite differences in the degree of shell alteration, suggesting that both weakly and strongly altered assemblages offer data with a high compositional fidelity. Carbonate‐rich terrestrial deposits originating in arid conditions can enhance the preservation of gastropods and result in fossil assemblages that are suitable for palaeoecological and palaeoenvironmental studies of terrestrial ecosystems.     

Typification of three taxa of the genus Festuca L. (Poaceae)

Lectotypifications of Festuca infesta Hack. ex Trab., Festuca maroccana Trab. and Festuca rubra L. subsp. scabrescens Hack. ex Trab. are designated here. The principal diagnostic characters and chorology are also presented for each taxon. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 342–343.     

The taxonomy of Galium crespianum J.J. Rodr. (Rubiaceae), a Balearic Islands endemic revisited

Galium crespianum J.J. Rodr. is a perennial plant inhabiting cliffs and crevices on the Balearic Islands. Although it was described from the mountains of Mallorca, several populations from the islands of Eivissa and Formentera have been traditionally considered as belonging to the same species. A careful comparison of specimens from the western and eastern Balearics revealed several discriminant features in gross morphology (robustness and habit of the stems, presence or absence of hairs at the internodes and leaves, waxiness of stems and leaves, shape of the inflorescence, flower colour and scent) and stem anatomy. In addition, several mutations in the ribosomal ITS sequences distinguished western and eastern plants. It is proposed that the plants from Eivissa and Formentera previously subsumed under G. crespianum be recognized at the specific level as G. friedrichii N. Torres, L. Saez, Mus & Rossello nom. nov. The new species is tetraploid (2n = 44) and shares morphological features with G. crespianum or with several taxa in the G. glaucum complex from the south east Iberian peninsula, to which it is most probably related.     

Isolation and characterization of microsatellite loci in the Pacific pleasure oyster,Crassostrea corteziensis,and their cross‐species amplification in four other oyster species

Microsatellite loci were isolated in Crassostrea corteziensis using (GT)_n, (CT)_n and (CTGT)_n‐enriched genomic libraries. Within each of 45 sequenced clones, an average of three microsatellite regions (156 total) were observed. Thirty‐three primers were designed, from which 11 microsatellite loci amplified. Ten of those were polymorphic, with a range of two to 30 alleles. Three loci were not in Hardy–Weinberg equilibrium, and linkage disequilibrium was found for six pairs of loci. These microsatellite loci will be further tested for segregation distortions and null alleles to establish a set for population genetic studies of the species in the Northwest coasts of Mexico, and for optimization of aquaculture development. Seven of the microsatellite loci cross‐amplified in Crassostrea palmula, a sympatric species, and will be useful in further genetic studies.     

Polymorphism of chloroplast microsatellite DNA loci in Russian potato cultivars

The cpSSR method was for the first time used to analyze the plastome in 29 Russian potato Solanum tuberosum cultivars. The informativeness coefficient H and the alleles of the NTCP6, NTCP8, and NTCP9 loci were determined. In total, 14 allelic variants of the microsatellite cpDNA loci were identified. The NTCP8 and NTCP9 cpSSR displayed the greatest allele polymorphism in the cultivars examined. A cultivar-specific haplotype of the chloroplast genome was observed for 20 out of 29 cultivars.     

Seed micromorphology in the genus Neotinea Rchb.f. (Orchidaceae, Orchidinae)

The ultrastructure of testa seed in the genus Neotinea (Orchidaceae, Orchidinae) was examined for the first time. The morphology of the seed and of the anticlinal and periclinal walls was analysed by scanning electron microscopy. Quantitative data concerning the length and width of the seed and embryo, seed and embryo volume, free air space, and number of cells along the longitudinal axis are presented. In all species, the seeds are fusiform in shape with transverse ridges on the inner periclinal walls. This ornamentation pattern is characteristic for the genus Neotinea . It is a good diagnostic value supporting the monophyly of this genus, which has recently been proposed by several authors.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 133–140.     

INVINH1 Gene Alleliс Polymorphism in Maize Accessions from VIR Collection

Russian Journal of Genetics - The sequences of the apoplastic invertase inhibitor gene INVINH1 were identified in 71 maize accessions from the collection of the Vavilov All-Russian Institute of...