Osmolyte concentrations in Atriplex halimus L. and Atriplex canescens (Pursh) Nutt. adapted to salinity and low temperature (Chenopodiaceae) Resumen

Concentración de osmolitos en Atriplex halimus L. y Atriplex canescens (Pursh) Nutt. adaptados a salinidad y bajas temperaturas (Chenopodiaceae) En este trabajo hemos investigado los efectos de la tolerancia a la congelación de Atriplex halimus y Atriplex canescens de diferentes poblaciones de Argelia. La tolerancia al frío se determinó mediante ensayos de pérdida de electrolitos en hojas de plantas que crecieron durante tres meses en maceta más un mes de aclimatación al frío. Para A. halimus se determinó el efecto que producía el incremento de salinidad en el suelo sobre la tolerancia al frío, comparando los niveles de cationes y osmolitos orgánicos en hojas de plantas que crecieron en soluciones salinas, con los de plantas que únicamente habían sido aclimatadas al frío. Se encontró una relación significativa entre la tolerancia al frío y la concentración de Na y Na + K en tejidos. Se relacionan los cambios en la concentración de osmolitos bajo condiciones de salinidad (cultivo hidropónico) con los cambios producidos mediante la interación de aclimatación al frío más salinidad del suelo. Palabras clave: Atriplex halimus, Atriplex canescens, Cationes, Halofitos, Salinidad, Solutos compatibles, Tolerancia al frío. Abstract We investigated the effects of cold (freezing) tolerance for Atriplex halimus and Atriplex canescens (Chenopodiaceae) from different locations in Algeria. Plants were grown in pots of soil for three months, after a one-month acclimation period, the cold tolerance was determined, in leaf electrolyte leakage assays. For A. halimus, the effect of increased soil salinity (addition of NaCl) on tolerance was determined and the cold-acclimated plants were compared with those grown in saline nutrient solution, in relation to leaf levels of cations and organic osmolytes. There was significant correlation between the cold tolerance and the leaf tissue water concentrations of Na and Na+K. Here we relate changes in osmolyte concentration under cold acclimation/soil salinisation

Estimación del contenido de ADN nuclear en poblaciones argelinas de Atriplex halimus y Atriplex canescens por citometría de flujo

Atriplex halimus is a perennial native shrub of the Mediterranean Basin with an excellent tolerance to drought and salinity, also, Atriplex canescens, four-wing saltbush, is adapted to desert climates. The aim of this work was to estimate nuclear DNA content in Algerian populations of A. halimus and A. canescens by flow cytometry, an efficient method to estimate ploidy levels and to de- termine nuclear DNA content in plants. Flow cytomertry is a technique which permits rapid estimation of nuclear DNA content. With respect to nuclear DNA, the 2C DNA content of population Cala Tarida (Spain) was estimated to be 2.46pg. There was no significant difference among the populations of A. halimus, whose 2C DNA content ranged from 4.91 to 5.04pg. However, the 2C DNA content of A. canescens ranged from 3.14 to 3.27.Atriplex halimus es un arbusto perenne nativo de la cuenca mediterránea con una excelente tolerancia a la sequía y la salinidad. Atriplex canescens, de origen americano, se adapta muy bien a los climas desérticos. El objetivo de este trabajo fue estimar el contenido de ADN nuclear en poblaciones argelinas de A. halimus y A. canescens por citometría de flujo, un método eficaz para estimar los niveles de ploidía y para determinar el contenido de ADN nuclear en las plantas. La citometría de flujo es una técnica que permite la estimación rápida de contenido de ADN nuclear. Con respecto al ADN nuclear, el ADN contenido 2C de la población de Cala Tarida (España) se estimó en 2.46pg. No hubo diferencias significativas entre las poblaciones de A. halimus, cuyo contenido 2C de ADN oscilaron entre 4,91 y 5.04pg. Sin embargo, el contenido 2C de ADN de A. canescens oscilaron entre 3,14 y 3,27

Concentración de osmolitos en Atriplex halimus L. y Atriplex canescens (Pursh) Nutt. adaptados a salinidad y bajas temperaturas (Chenopodiaceae)

Concentración de osmolitos en Atriplex halimus L. y Atriplex canescens (Pursh) Nutt. adaptados a salinidad y bajas temperaturas (Chenopodiaceae) En este trabajo hemos investigado los efectos de la tolerancia a la congelación de Atriplex halimus y Atriplex canescens de diferentes poblaciones de Argelia. La tolerancia al frío se determinó mediante ensayos de pérdida de electrolitos en hojas de plantas que crecieron durante tres meses en maceta más un mes de aclimatación al frío. Para A. halimus se determinó el efecto que producía el incremento de salinidad en el suelo sobre la tolerancia al frío, comparando los niveles de cationes y osmolitos orgánicos en hojas de plantas que crecieron en soluciones salinas, con los de plantas que únicamente habían sido aclimatadas al frío. Se encontró una relación significativa entre la tolerancia al frío y la concentración de Na y Na + K en tejidos. Se relacionan los cambios en la concentración de osmolitos bajo condiciones de salinidad (cultivo hidropónico) con los cambios producidos mediante la interación de aclimatación al frío más salinidad del suelo

Influence of natural habitat fragmentation on the genetic structure of Canarian populations of Juniperus turbinata

Oceanic archipelagos provide an important platform from which to evaluate the effects of isolation and fragmentation on the genetic structure of species. As a result of oceanic isolation, such species usually show lower levels of genetic diversity and higher genetic differentiation than their mainland congeners. However, this is not necessarily the case for long distance dispersal species, whose genetic structure is not strictly defined by population isolation. We assessed the level and distribution of genetic diversity among Canarian populations of in order to evaluate the influence of population isolation on its genetic structure. Using Amplified Fragment Length Polymorphism markers, we analyzed molecular diversity among 175 individuals from five populations occurring across the Canary Island and three Moroccan populations. Principal Coordinate Analysis, neighbor joining clustering, AMOVA and Bayesian-based analysis were applied to examine population structure. Despite the documented habitat loss and decline in Canarian populations, Amplified Fragment Length Polymorphism markers revealed levels of intra-population genetic diversity that were similar to those from mainland populations, and low levels of genetic differentiation. Bayesian analysis of population structure showed three main clusters, one comprising El Hierro population and a few individuals from several islands, a second cluster that grouped the remaining Canarian populations together, and a third cluster grouping Moroccan populations. Our results suggest that the main force driving the genetic structure of Canarian populations of is its capacity for long distance dispersal.Juniperus turbinataJ. turbinat

Genetic structure and phylogeography of Juniperus phoenicea complex throughout Mediterranean and Macaronesian regions: different stories in one

International audienceAbstractKey messageThe genetic structure ofJuniperus phoeniceain the Mediterranean Basin is inferred using amplified fragment length polymorphism markers (AFLP) markers. As other Mediterranean conifers,J. phoeniceapopulations show moderate levels of genetic diversity and interpopulational differentiation. The pattern of distribution of genetic diversity seems highly influenced by the climatic fluctuations which occurred in the Pleistocene.ContextIt has been stated that the genetic structure of Mediterranean conifers is mediated by the historical climatic changes and the geological rearrangements which occurred in the Mediterranean Basin. J. phoenicea provides an excellent example to test how its genetic structure is influenced by these events.AimsIn this work, we study the amount and distribution of genetic diversity of J. phoenicea complex, in order to evaluate its taxonomic status and to reveal underlying phylogeographic patterns.MethodsThe molecular diversity was analyzed for 805 individuals from 46 populations throughout its distribution range using AFLP markers. Principal coordinate analysis, analysis of molecular variance (AMOVA), and Bayesian-based analysis were applied to examine the population structure.ResultsAFLP markers revealed moderate levels of intrapopulation genetic diversity, pairwise genetic differentiation, and a clear pattern of isolation by distance. Bayesian analysis of population structure showed five clusters related to the taxonomic status of J. phoenicea and J. turbinata, and a geographic pattern of genetic structure in J. turbinata.ConclusionAll the analysis separate J. phoenicea from J. turbinata. For J. turbinata, up to four groups can be distinguished from a phylogeographic point of view. The genetic structure of J. turbinata seems highly influenced by climatic and geologic fluctuations occurring since the Oligocene

Admixture and local breed marginalization threaten Algerian sheep diversity

Due to its geo-climatic conditions, Algeria represents a biodiversity hotspot, with sheep breeds well adapted to a patchwork of extremely heterogeneous harsh habitats. The importance of this peculiar genetic reservoir increases as climate change drives the demand for new adaptations. However, the expansion of a single breed (Ouled-Djellal) which occurred in the last decades has generated a critical situation for the other breeds; some of them are being subjected to uncontrolled cross-breeding with the favored breed and/or to marginalization (effective size contraction). This study investigated genetic diversity within and among six of the nine Algerian breeds, by use of 30 microsatellite markers. Our results showed that, in spite of the census contraction experienced by most of the considered breeds, genetic diversity is still substantial (average gene diversity ranging 0.68 to 0.76) and inbreeding was not identified as a problem. However, two breeds (Rembi and Taadmit) appeared to have lost most of their genetic originality because of intensive cross-breeding with Ouled-Djellal. Based on the above evidence, we suggest Hamra, Sidaoun, and D'man as breeds deserving the highest priority for conservation in Algeria

Pair-wise F_ST among Algerian breeds (a) and Italian breeds (b), calculated with a common set of 15 microsatellites^* (with confidence intervals at 95%).

<p>Ba, Bagnolese; Co, Comisana; Ge, Gentile Di Puglia; La, Laticauda; Le, Leccese; Sa, Sarda.</p><p>*the common set of microsatellites was: MAF65, MAF214, OARFCB304, ILST11, OARAE129, OARFCB193, MAF209, OARJMP58, ILST5, OARFCB128, INRA63, BM1824, MAF33, MCM140, BM8125.</p><p>Pair-wise F_ST among Algerian breeds (a) and Italian breeds (b), calculated with a common set of 15 microsatellites^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0122667#t003fn002" target="_blank">*</a>} (with confidence intervals at 95%).</p

Pair-wise F_ST among Algerian breeds (with confidence intervals at 95%).

<p>Pair-wise F_ST among Algerian breeds (with confidence intervals at 95%).</p