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  • 1
    Electronic Resource
    Electronic Resource
    Genetic variation inOrchis papilionacea (Orchidaceae) from the Central Mediterranean region: Taxonomic inferences at the intraspecific level (1995)
    Springer
    Plant systematics and evolution 194 (1995), S. 9-23 
    Details
    ISSN: 1615-6110
    Keywords: Orchidaceae ; Orchis ; O. papilionacea ; subsp.papilionacea ; subsp.grandiflora ; subsp.heroica ; Multilocus electrophoresis ; genetic structure ; gene flow ; genetic distance ; biochemical taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The genetic differentiation ofOrchis papilionacea from Italy, Corsica, Sardinia, Sicily, and Greece was analyzed by isozyme studies. No significant differences at any of the 28 loci tested were observed between samples of the putative subspeciespapilionacea from Italy,grandiflora from Sicily andheroica from Greece, or by comparing sympatricpapilionacea-like andgrandiflora-like subsamples from Sardinia and Corsica. The genetic relationships found among the populations studied reflect more their geographic origin than their taxonomic assignment;papilionacea, grandiflora, andheroica are, therefore, at least in the study area, not to be considered as subspecies, but as simple morphs, controlled by few genes (possibly two) with Mendelian inheritance. The genetic divergence observed among the samples studied is very low and consistent with that of geographic populations of a single cohesive gene pool, linked by a high gene flow (Nm = 5.9).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00983213
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  • 2
    Electronic Resource
    Electronic Resource
    Genetic variation and natural hybridization betweenOrchis laxiflora andOrchis palustris (Orchidaceae) (1996)
    Springer
    Plant systematics and evolution 202 (1996), S. 87-109 
    Details
    ISSN: 1615-6110
    Keywords: Orchidaceae ; Orchis laxiflora ; O. palustris ; Isozymes ; genetic structure ; gene flow ; genetic distance ; chromosome number ; hybridization ; biochemical taxonomy ; endangered species
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Genetic divergence between population samples ofOrchis laxiflora and ofO. palustris from various European locations was studied by electrophoretic analysis of 25 enzyme loci. An average genetic distance of DNei = 1.24 was found between the two taxa, with 12 out of 25 loci showing alternative alleles (diagnostic loci). Genetic heterogeneity was observed within bothO. laxiflora andO. palustris, when northern and southeastern populations were compared, being lower in the former taxon (D = 0.06), than in the latter (D = 0.16). Karyologically, 2n = 36 was found for bothO. laxiflora andO. palustris. O. laxiflora andO. palustris produce hybrids, described asO. ×intermedia. Genotype analysis of several sympatric samples showed the presence of hybrid zones, including F1 hybrids and, in low proportions, recombinant classes, putatively assigned to Fn and backcrosses, as well as a few introgressed individuals of both taxa. These data indicate that hybrids are only partially fertile, with a very limited mixing up of the two parental gene pools; this is also shown by the lack of significant lowering of genetic distances when sympatric and allopatric heterospecific samples are compared. Accordingly,O. laxiflora andO. palustris form a syngameon; nevertheless they can be considered as good taxonomic species, with virtually distinct gene pools, which evolve independently. The genetic variability inO. laxiflora andO. palustris is remarkably low ( $$\bar H$$ e = 0.05 and $$\bar H$$ e = 0.02, respectively). In particular, nearly complete absence of polymorphic loci was found inO. palustris from northcentral Europe. Two hypotheses are considered to explain the low genetic variability of this endangered species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00985819
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  • 3
    Electronic Resource
    Electronic Resource
    Allozyme and morphological identification of shape Anisakis, Contracaecum and Pseudoterranova from Japanese waters (Nematoda, Ascaridoidea) (1998)
    Springer
    Systematic parasitology 40 (1998), S. 81-92 
    Details
    ISSN: 1573-5192
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Allozyme markers were used to identify anisakid nematodes from marine Japanese waters, morphologically assigned to three species complexes: Anisakis simplex (s. l.), Contracaecum osculatum (s. l.) and Pseudoterranova decipiens (s. l.). Samples assigned to A. simplex (s. l.) were found to correspond genetically to A. simplex sensu stricto, those of C. osculatum (s. l.) to C. osculatum A. No morphological characters are yet available to distinguish sibling species of these two complexes. As to the P. decipiens complex, two distinct species were detected: the first corresponded to P. decipiens C, previously recovered in the northern Atlantic, the second to P. decipiens D from Japan. The two species are genetically well differentiated, with five of the 19 loci tested showing distinct fixed alleles. Their reproductive isolation was proved by the lack of hybrids or recombinants in sympatric samples recovered from the same definitive host, Erignathus barbatus. P. decipiens D was found to correspond morphologically to Porrocaecum azarasi, previously considered a synonym of P. decipiens. Accordingly, the name Pseudoterranova azarasi (Yamaguti & Arima, 1942) n. comb. is proposed for P. decipiens D. Similarly, P. decipiens C fits in general morphology, type-locality and host with Ascaris bulbosa, also previously considered a synonym of P. decipiens. The name Pseudoterranova bulbosa (Cobb, 1888) n. comb. is proposed for P. decipiens C.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005914926720
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  • 4
    Electronic Resource
    Electronic Resource
    A new species of Anisakis Dujardin, 1845 (Nematoda, Anisakidae) from beaked whales (Ziphiidae): allozyme and morphological evidence (1998)
    Springer
    Systematic parasitology 40 (1998), S. 161-174 
    Details
    ISSN: 1573-5192
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Larvae and adults of Anisakis, recovered from the beaked whales Mesoplodon layardii and Ziphius cavirostris from the Mediterranean Sea and South African waters, were analysed morphologically and by molecular markers (allozymes). A new Anisakis species was identified, showing fixed allele differences at a number of loci from the other Anisakis spp. tested (A. simplex complex, A. physeteris). The lack of hybrid or recombinant genotypes in mixed infections with A. pegreffii, A. simplex C and A. physeteris, as well as the high values of genetic distance (average DNei = 1.65 from the members of the A. simplex complex, and DNei = 3.09 from A. physeteris) showed that the new species is reproductively isolated. This new Anisakis species is morphologically different from the other Anisakis retained by Davey (1971) as either good species or species inquirendae. The name Anisakis ziphidarum n. sp. is proposed for the new species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006093201920
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    Paper (German National Licenses)
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  • 5
    Electronic Resource
    Electronic Resource
    Pseudoterranova decipiens species A and B (Nematoda, Ascaridoidea): nomenclatural designation, morphological diagnostic characters and genetic markers (2000)
    Springer
    Systematic parasitology 45 (2000), S. 185-197 
    Details
    ISSN: 1573-5192
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Five genetically distinct and reproductively isolated species have been detected previously within the morphospecies Pseudoterranova decipiens from the Arctic-Boreal, Boreal and Antarctic. Morphological analysis was carried out on male specimens identified by genetic (allozyme) markers, allowing the detection of significant differences at a number of characters between two members of the P. decipiens complex, namely P. decipiens A and B. On the basis of such differences, the nomenclatural designation for the two species is discussed. The names Pseudoterranova krabbei n. sp. and P. decipiens (sensu stricto) are proposed for species A and B, respectively. Morphological and genetic differentiation between the two species is shown using multivariate analysis. Allozyme diagnostic keys for routine identification of the four members of the P. decipiens complex, namely P. decipiens (s.s.), P. krabbei, P. bulbosa and P. azarasi, irrespective of sex and life-history stage, are provided.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006296316222
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    Paper (German National Licenses)
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