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We used allozyme electrophoresis to survey genetic diversity of Agrostis barceloi L.Sáez & Rosselló, an extremely narrow endemic species from the island of Majorca (Balearic Islands, Western Mediterranean Basin). This species is a tetraploid with a single natural population of less than 100 individuals. All analyzed individuals of A. barceloi showed the same genotype. Four out of 18 interpretable loci showed fixed heterozygosity (thus supporting an allopolyploid origin). The genotypic uniformity of this species may be attributed to a founder effect associated with a dispersal event of its ancestor from the continent, a very small current effective population size ( N), and a series of natural or anthropogenic threats affecting the population. We propose several conservation measures such as seed storing and plant production for further reinforcements (which do not need any previous work for selecting individuals because of the genetic uniformity). In addition, we suggest the preservation of the mountain summit where the species is found (Puig Major), which would also positively influence the conservation of other co-occurring ENEs and other rare and threatened species. [ABSTRACT FROM AUTHOR]

Allozyme diversity was assessed in 13 populations of Delphinium pictum and D. requienii, two short-lived and closely related insular Mediterranean endemics. While D. pictum has scattered distribution in Corsica, Sardinia and Majorca, D. requienii is found in a few small populations restricted to the Hyères Archipelago. Eleven enzyme systems were assayed, and 15 loci were resolved. Both species harboured moderate levels of genetic diversity, comparable to the values expected for endemic plants. All genetic parameters suggested higher diversity in D. pictum ( A = 1.93, P = 40, He = 0.106) than in D. requienii ( A = 1.30, P = 26.7, He = 0.096); FIS values revealed higher inbreeding in D. requienii. Although the two species did not harbour species-specific alelles in the surveyed loci, the UPGMA dendrogram based on Nei’s genetic similarity index supported divergence between them. These results, together with significant morphological similarity and evidence of successful hybridization between the species, support the hypothesis of a recent speciation event. The moderate levels of both genetic variability and population divergence observed for D. pictum are likely attributable to its ability to establish seed banks. Given that the allozyme variation detected for D. pictum was significantly partitioned among islands, we suggest the implementation of conservation programs throughout its distribution range, and not only in Corsica as it occurs nowadays. Management strategies are also desirable for D. requienii to maintain population size and control inbreeding. [ABSTRACT FROM AUTHOR]

Allozyme electrophoresis was conducted to survey the levels and distribution of genetic diversity in the tetraploid perennial larkspur Delphinium montanum (Ranunculaceae), which is endemic to the eastern Pyrenees of Spain and France and considered to be endangered. Seven populations were sampled, resolving 14 putative enzymatic loci belonging to eight enzymes. Banding patterns stained in gels revealed several enzymatic duplications attributable to autotetraploidy, such as the presence of both balanced and unbalanced heterozygotes and the lack of fixed heterozygosity. However, variability in D. montanum ( P = 23.8%, A = 1.48, and He = 0.082) was lower than that expected for an autotetraploid species. This, in addition to the scarcity of loci showing three or four different alleles, could indicate that this species has suffered genetic erosion through population bottlenecks, or, alternatively, that it is undergoing diploidization. © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society, 2007, 155, 211–222. [ABSTRACT FROM AUTHOR]

• Background and AimsThymus loscosii (Lamiaceae) is a tetraploid perennial species endemic to the Ebro river basin (north‐eastern Spain), which is included in the National Catalogue of Endangered Species. It is a tetraploid species (2n = 54), presumably an autotetraploid originated by the duplication of a 2n = 28 genome and the subsequent loss of two chromosomes. Allozyme electrophoresis was conducted to survey the levels and distribution of genetic diversity and to test the previous autopolyploid hypothesis for its origin. In addition, both in situ and ex situ conservation measures are proposed.• Methods Eight populations were sampled for analysis by standard methods of starch gel electrophoresis, and six putative enzymatic loci were resolved (five consistently and one only partially).• Key Results Banding patterns exhibited no evidence of fixed heterozygosity and showed both balanced and unbalanced heterozygotes. In addition, most individuals showed a pattern consistent with the presence of three or four alleles at a single locus. High levels of genetic variability were found at population level (P = 85 %, A = 3·0, He = 0·422), in addition to a trend of an excess of heterozygotes.• Conclusions Allozyme data support the hypothesis that T. loscosii is an autotetraploid, and the high number of alleles at some loci may be due to repeated polyploidization events. The high values of genetic variation found in this species agree with those expected for tetraploids. The excess of heterozygotes may be due to some barriers to inbreeding (e.g. occurrence of gynodioecy) and/or selection for heterozygosity. [ABSTRACT FROM AUTHOR]

Starch gel electrophoresis was used to evaluate the allozyme diversity, population structure, and taxonomic relationships of two closely related taxa endemic to the Iberian Peninsula: Petrocoptis montsicciana O. Bolòs & Rivas Martínez, restricted to the pre-Pyrenean belt of Catalonia and Aragon, and Petrocoptis pardoi Pau, endemic to the Bergantes River basin (Autonomous Community of Valencia). Seven populations of the two species were sampled, and 16 interpretable loci were found. Considerable polymorphism, more than expected in endemic species, was detected in both taxa. The percentage of polymorphic loci (P) when the most common allele had a frequency of <0.95, the mean number of alleles per locus (A), and the expected panmictic heterozygosity (H[sub e] ) were slightly higher in P. montsicciana (P = 70.3, A = 2.2 and H[sub e] = 0.239) than in P. pardoi (P = 56.3, A = 1.9 and H[sub e] = 0.192). Strong divergence between populations was found in both species (G[sub ST] = 0.376 in P. montsicciana and G[sub ST] = 0.354 in P. pardoi) because of the geographic isolation of populations and limited seed and pollen dispersal. Most loci showed deviations from the Hardy-Weinberg equilibrium, probably as a consequence of genetic substructuring of populations. Low germination and renewal rates, and some anthropogenic activities such as road work, climbing, and massive collection are the main threats to these species.Key words: Petrocoptis montsicciana, Petrocoptis pardoi, Caryophyllaceae, allozyme electrophoresis, genetic diversity, conservation, endemic species.Nous avons utilisé l'électrophorèse sur gels d'amidon pour évaluer la diversité allozymique, la structure des populations et les rapports taxonomiques de deux taxons étroitement apparentés endémiques de la péninsule ibérique: le Petrocoptis montsicciana O. Bolòs & Rivas Martínez, limité à la ceinture pré-pyrénéenne de la Catalogne et l'Aragon, et le Petrocoptis pardoi Pau, endémique du bassin de la rivière Bergantes (Pays Valencien). Sept populations des deux espèces ont été échantillonnées et 16 loci interprétables ont été décelés. Un polymorphisme plus grand que celui attendu chez une espèce endémique a été trouvé dans les deux taxons. Le pourcentage de loci polymorphiques (P) lorsque l'allèle le plus commun a une fréquence <0,95, le nombre moyen d'allèles par locus (A), et l'hétérozygocité panmictic attendue (H[sub e] ) sont un peu plus élevé chez le P. montsicciana (P = 70,3, A = 2,2 et H[sub e] = 0,239) que chez le P. pardoi (P = 56,3, A = 1,9 and H[sub e] = 0,192). Une forte divergence entre les populations a été trouvée chez les deux espèces (G[sub ST] = 0,376 chez P. montsicciana et G[sub ST] = 0,354 chez le P. pardoi), à cause de l'isolement géographique des populations et la limitation dans la dispersion des graines et du pollen. La plupart des loci montraient des écarts de l'équilibre de Hardy-Weinberg, probablement comme une conséquence de la sous-structuration génétique des populations. Les faibles taux de germination et de renouvellement, ainsi que des activités anthropiques, telles que les travaux routiers, l'escalade et la récolte massive sont les menaces principales pour ces espèces.Mots clés : Petrocoptis montsicciana, Petrocoptis pardoi, Caryophyllaceae, électrophorèse d'alloenzymes, diversité génétique, conservation, espèces endémiques. [ABSTRACT FROM AUTHOR]

Abstract: Aquilegia paui is a narrow endemic species from the north-eastern Iberian Peninsula. It has a reduced number of populations in the limestone mountain massif of Els Ports. Genetic diversity was evaluated through allozyme electrophoresis in this rare columbine, together with its widespread congener Aquilegia vulgaris. Low levels of genetic diversity were detected in both taxa, especially for A. paui. Genetic identity between the two columbines was particularly high (I = 0.990), and the allele pool of A. paui is a subset of that of its widespread congener (with the exception of a low-frequency allele that was only detected in one population of A. paui). A. paui may have recently evolved from nearby populations of A. vulgaris. Speciation of this taxon, which may still be ongoing, seems to be driven by ecological differentiation, as generally occurred for the European columbines as well as in many Mediterranean endemic species. [Copyright &y& Elsevier]