Genetic variation and conservation of the endangered endemic Anagyris latifolia Brouss. ex Willd. (Leguminosae) from the Canary Islands

Anagyris latifolia is an endemic and endangered species from the Canary Islands, whose distribution is limited to four islands, with less than 400 individuals in fragmented and isolated localities. RAPD markers have been used to assess the genetic diversity and genetic differentiation of its populations, in order to formulate appropriate management and conservation genetics strategies. Nine polymorphic primers generated 74 polymorphic DNA fragments. Genetic variation levels detected in Anagyris latifolia were significant high (H = 0.200; P% = 97.3), principal coordinates analysis and genetic differentiation coefficient showed a high degree of genetic differentiation between islands, without a define east-to-west stepping stone colonization route. AMOVA analysis showed that of the total genetic variation detected, 32.43% was maintained among islands, 20.73% contained among population within islands, and 46.84% resided within populations. According to these results, management strategies should be focused on each island separately.     

Interspecific hybridization between diploid species of Lotus (Leguminosae)

An interspecific hybridization study has been carried out between seven diploid species of Lotus (L. alpinus Schleich., L. japonicus (Regel) Larsen, L. filicaulis Dur., L. schoelleri Schweinf., L. krylovii Schischk. and Serg., L. tenuis Waldst. et Kit., and L. corniculatus var. minor Baker) closely related to L. corniculatus L. A total of 139 interspecific hybrids were produced in 16 combinations of the 7 species. Nine of these crosses were produced for the first time and four were obtained by means of embryo-culture. The growth habit, number of florets per umbel, flower color expression, HCN reaction and 15 metrical traits were compared between parents and hybrids. The relative case with which some hybrids were produced suggested that during the early evolutionary history of the genus species diversification could have originated through interspecific hybridization and subsequent gene differentiation. In some crosses, the hybrids resembled one parent more closely than the other. This close morphological affinity between the hybrids and one of their parents would make it extremely difficult to detect such hybrids in natural populations and probably aceounts for the prevailing belief that there is little or no hybridization in nature.     

Chromosome differentiation in diploid species of Lotus (Leguminosae)

Summary Meiotic chromosome behavior was studied in seven diploid species of Lotus (L. alpinus Schleich., L. japonicus (Regel) Larsen, L. filicaulis Dur., L. schoelleri Schweinf., L. krylovii Schischk. and Serg., L. tenuis Waldst. et Kit., L. corniculatus var. minor Baker) and in 51 interspecific hybrids from 16 different crosses. Meiosis in the diploid species was quite regular. In a high proportion of the PMC's of the hybrids there was close chromosome homology with a normal association of 6 II's. However, meiotic irregularities including bridges, lagging chromosomes, univalents, and quadrivalents, occurred in a small percentage of the cells. The late separation of bivalents, the presence of quadrivalents, and inversion bridges with fragments, would indicate for some hybrids that certain chromosomes were structurally differentiated. The large number of rod bivalents observed at diakinesis was also highly suggestive that genetic nonhomology in one chromosome arm could contribute to the frequency of this type of bivalent. Therefore, the maximum number of 6 II's which occurred in a high percentage of cells may be misleading in that cryptic structural differences between chromosome arms, or segments, are not revealed. Pollen fertility in the species and hybrids was not correlated with meiotic irregularities suggesting that pollen fertility is genotypically controlled.     

A new species of Lepidasthenia (Polychaeta, Polynoidae) from Canary Islands

Lepidasthenia medanensis spn, is described from subtidal sandy bottom and beds of Cymodoceanodosa on the south west coast of Tenerife, Canary Islands.     

Regeneration strategies of tree species in the laurel forest of Tenerife (The Canary Islands)

The laurel-forest of the Canary Islands is a montane cloud-forest. In order to gain some knowledge on the processes that maintain tree species diversity, we conducted an analysis of three different laurel-forest plots of the Anaga massif (Tenerife), varying in canopy composition but growing under similar environmental conditions. For each plot we recorded basal area of the canopy trees (h<1.30 m), the density of suckers and seedlings (h>1.30 m), as well as seed-bank composition. The plots have similar regeneration composition, which appears to be independent of differences in canopy composition. Laurus azorica is the most common seedling species, whereas Prunus lusitanica is the most abundant species among suckers and basal shoots. Neither Erica arborea nor Myrica faya, the two main canopy trees in one of the plots, were found in any of the stands as seedlings or suckers, despite their existence as viable seeds in the seed-bank. The regeneration composition and the canopy composition in one of the plots is remarkable different, revealing differents dynamics processes in the three plots. The results suggest the existence of three well-defined ecological groups: pioneer (regeneration primarily by seedlings), non-pioneer (regeneration by seedlings and suckers) and remnant species (regeneration primarily by suckers).These three groups and the effect of small scale disturbances (natural and human-induced), could help to understand the maintenance of tree species richness.     

Overcoming seed dormancy in ex situ plant germplasm conservation programmes; an example in the endemic Argyranthemum (Asteraceae: Anthemideae) species from the Canary Islands

Germplasm of 21 diverse Argyranthemum taxa was collected from contrasting ecological zones in the Canary Islands. Seed dormancy was considerable in the majority of taxa. Extensive investigations, based on a germination test procedure algorithm for Asteraceae, with achenes from ray and disc florets of five contrasting taxa identified a procedure to promote full (85%) germination of the seeds from both ray and disc florets of all five taxa; viz, excision of the seeds from the achenes, followed by testing at 15°C with 2.6×10^-3 m GA₃ co-applied. Subsequent tests showed that this regime was effective in promoting full germination in seeds from both ray and disc florets of the remaining 16 taxa. The results are discussed in the context of ex situ plant germplasm conservation.     

Lecanora sabinae, a new lichen species from the Canary Islands

Lecanora sabinae sp. nov. from the Canary Islands (El Hierro and La Gomera) is characterized chiefly by its greenish thallus with abundant pruinose apothecia ranging in colour from light yellow to almost black. It contains usnic acid, zeorin, and an unknown chemical product SAB-1, is by preference lignicolous and lives in association with the conifer Juniperus phoenicea.     

Gerronema wildpretii sp. nov. (Agaricales, Basidiomycetes) a new species from the Canary Islands

Gerronema wildpretii, collected in climactic sites of the monteverde forest of the Canary Islands is described and illustrated. Its macro- and microscopic features delimit this taxon as a new species.     

The helminth community of the skink Chalcides sexlineatus from Gran Canaria (Canary Islands)

A survey of the gastrointestinal helminth communities of a population of Chalcides sexlineatus Steindachner, a small skink endemic to Gran Canaria island (Canary Archipelago, Spain), was conducted to determine the prevalence, abundance and species diversity of intestinal parasites in these reptiles. Only three parasite species were found, one cestode, Oochoristica agamae Baylis, 1919 and two nematodes, Parapharyngodon micipsae (Seurat, 1917) and Pharyngodonidae gen. sp. Helminth infracommunities of C. sexlineatus showed low values of abundance and species richness and diversity, being more similar to the helminth community of Tarentola boettgeri boettgeri (Steindachner) rather than those of Gallotia stehlini (Schenkel), both syntopic with the sampled host.     

Isozyme variation in Calliandra calothyrsus (Leguminosae): its implications for species delimitation and conservation

Patterns of genetic diversity within and among populations of Calliandra calothyrsus, an important multipurpose tree species, were examined using isozyme analysis. C. calothyrsus is a widespread species distributed throughout Central America and southern Mexico, across a variety of environments. Morphologically and ecologically distinct populations can be identified within this range, but they are currently considered to represent a single species. C. calothyrsus has been introduced to many parts of the tropics, where it is cultivated as a source of fuelwood, animal fodder, green manure, and shade by rural communities. Some of these introductions are known to have originated from Guatemala, but very little is known about the genetic diversity of either the native or naturalized populations. Isozyme electrophoresis of 23 loci across 17 populations of C. calothyrsus indicated that the majority of genetic diversity was partitioned between populations (FST = 0.802) and that within-population heterozygosity was low (mean Ho = 0.057). Naturalized populations had lower than expected heterozygosities and were most similar to material from Santa Maria de Jesus, a natural population in southern Guatemala. Four distinct groups of populations were identified on the basis of Nei's genetic distances and Population Aggregation Analysis (PAA), and correlate with the morphological and ecological differences that can be observed within the species. The results are discussed in relation to species delimitation and conservation.     

Pollen characterization of multifloral honeys from La Palma (Canary Islands)

The pollen content of twenty-five honey samples from twelve different apiaries on La Palma (Canary Islands) was subjected to qualitative and quantitative melissopalynological analysis. The quantitative analysis showed that 4% of the honey belonged to Maurizio Class II, 88% to Class III, 4% to Class IV and 4% to Class V. In the qualitative analysis, 60 pollen types were identified from 40 different families. The number of pollen types per honey sample ranges between 16 and 37 (mean of 25.8). Foeniculum vulgare-type and Rumex sp. pollen were present in all the samples. Castanea sativa and Echium plantagineum pollen were found in 96% of them and the combination Aspalathium bituminosum, Bidens pilosa-type and Erica arborea in 92%.     

Climatic responses of plant species on Tenerife,The Canary Islands

Abstract. The distribution of 44 common vascular plant species on Tenerife, The Canary Islands, has been related to the variation in temperature and precipitation. Frequency values for these speceis were obtained using a stratified sampling system with 200 10 m x 10 m plots distributed all over the island. A model is proposed relating variation in vegetation to altitude according to two main climatic gradients occurring between the 3718 m summit and the coastline of Tenerife. The vascular plants have been classified into guilds according to their presumed tolerance to cold and drought; one remainder group includes species which are randomly distributed without any relation to climatic variation. Differences between the guild structure suggested here and common knowledge of plant species occurrence in the well-known vegetation belts of Tenerife are explained by assuming disturbance and local ground-water availability as additional decisive factors.     

Astragalus neobarnebyanus (Leguminosae): A new species from Peru

Astragalus neobarnebyanus, a new Peruvian species from Lomas de Atiquipa. Dept. Arequipa, is described and illustrated; its relationships with other South American species are discussed.     

Paleonutritional analysis on the prehispanic population from la palma (Canary Islands)

In this study, we determine bone strontium, barium, and calcium, as well as zinc, copper, and iron, in prehispanic samples belonging to adult individuals from the two main funerary caves from La Palma (Espigón and Barranco Porto), comparing them with our own modern controls. We have found that the Ba/Sr molar ratio of the individuals from Barranco Porto are significantly lower than that of the individuals from Espigón, thus suggesting a consumption of a marine-based diet by the former.