Search results for "Ang"

Conservation of the endangered Mediterranean tortoise Testudo hermanni hermanni: The contribution of population genetics and historical demography

2016

International audience; Estimating the genetic variation and demographic trends of species in decline is of major concern in conservation genetics. This study contributes to understanding how historical and anthropogenic factors shape the distribution of current genetic diversity in one of the most endangered reptiles in Western Europe, the Hermann's tortoise Testudo hermanni hermanni. We used 17 microsatellite loci, chosen from a pyrosequencing library specifically developed for the subspecies to genotype eight populations distributed over about 30 sample localities covering almost the entire geographic distribution of the sub-species. The population genetic results reflect a very strong g…

Northern European Salmo trutta (L.) populations are genetically divergent across geographical regions and environmental gradients

2020

The salmonid fish Brown trout is iconic as a model for the application of conservation genetics to understand and manage local interspecific variation. However, there is still scant information about relationships between local and large-scale population structure, and to what extent geographical and environmental variables are associated with barriers to gene flow. We used information from 3,782 mapped SNPs developed for the present study and conducted outlier tests and gene–environment association (GEA) analyses in order to examine drivers of population structure. Analyses comprised >2,600 fish from 72 riverine populations spanning a central part of the species' distribution in norther…

Spatio-temporal dynamics of genetic variation in the Iberian lynx along its path to extinction reconstructed with ancient DNA

2017

here is the tendency to assume that endangered species have been both genetically and demographically healthier in the past, so that any genetic erosion observed today was caused by their recent decline. The Iberian lynx (Lynx pardinus) suffered a dramatic and continuous decline during the 20th century, and now shows extremely low genome- and species-wide genetic diversity among other signs of genomic erosion. We analyze ancient (N = 10), historical (N = 245), and contemporary (N = 172) samples with microsatellite and mitogenome data to reconstruct the species' demography and investigate patterns of genetic variation across space and time. Iberian lynx populations transitioned from low but …

Influence of an evoked pleasant consumption context on consumers’ hedonic evaluation for minimally processed cactus pear (Opuntia ficus-indica) fruit

2016

Awareness of the need to consider a consumption context when measuring the consumer's hedonic evaluation of a food product led researchers to investigate differences among responses given by consumers in different contexts. Previous studies measured the effects of evoking a consumption context, by using photographs or a written scenario, on hedonic evaluations of consumers for food products. This study investigated the influence of evoking a consumption context on hedonic evaluation of minimally processed cactus pear (Opuntia ficus-indica) fruit, using pictures and memories of pleasant personal experiences. A hedonic scale method for measuring food preferences was used. Hedonic evaluation o…

Natural Biostimulants Elicit Plant Immune System in an Integrated Management Strategy of the Postharvest Green Mold of Orange Fruits Incited by Penic…

2021

This study was aimed at testing the integrated use of a natural biostimulant based on seaweed (Ascophyllum nodosum) and plant (alfalfa and sugarcane) extracts and reduced dosages of the conventional synthetic fungicide Imazalil (IMZ) to manage postharvest rots of orange fruits. The following aspects were investigated: (i) the effectiveness of postharvest treatment with natural biostimulant alone or in mixture with IMZ at a reduced dose against green mold caused byPenicillium digitatum; (ii) the differential expression of defense genes in orange fruits treated with the natural biostimulant both alone and in combination with a reduced dose of IMZ; (iii) the persistence of the inhibitory activ…

The late Pleistocene origin of the Italian and Maltese populations of Potamon fluviatile (Malacostraca: Decapoda): insights from an expanded sampling…

2017

Evidence available for most inland water and terrestrial organisms highlights the significant role played by southern Italy, Sicily and the Maltese islands as refuges during Pleistocene climatic fluctuations. However, to date, the hypothesis that these areas may have acted as Pleistocene refugia for the freshwater crab Potamon fluviatile has not been explicitly tested, and a recent origin of local P. fluviatile populations was proposed on the basis of a small set of analysed molecular data. We have thus expanded the currently available data set on the population genetic structure of P. fluviatile through dedicated samplings in Sicily (Italy, 18 specimens), the Maltese Islands (Malta, 15 spe…

Phylogeography ofSyringa josikaea(Oleaceae): Early Pleistocene divergence from East Asian relatives and survival in small populations in the Carpathi…

2015

Tertiary relict plant species of Europe have had a large distribution range before the Pleistocene but today are confined to small refugial areas. Syringa josikaea of the largely East Asian genus Syringa is a shrub of temperate forests in the Carpathians, restricted to altogether 25 small populations in two disjunct areas, the Apuseni Mountains (Romania) and the Ukrainian Carpathians. Miocene and Pleistocene fossil remains indicate the long-term presence of the species in Central Europe; hence S. josikaea has been considered a Tertiary relict. We aimed at clarifying the historical biogeography of S. josikaea by estimating the divergence time between S. josikaea and its Asian relatives, and …

2017

By the possession of unique exocrine scent glands, Opiliones (harvestmen) arise as a perfect model for studies on the evolutionary history of secretion chemistry. Among gland compounds of harvestmen, it is the quinones that represent recurring elements across the secretions of all suborders. Reliable data on quinone-distribution, however, is only known for Laniatores (benzoquinones) and Cyphophthalmi (naphthoquinones). We here unraveled the quinone-distribution across scent gland secretions of the third large harvestman suborder, the Palpatores (= Eu- and Dyspnoi): Naphthoquinones were found in phalangiid Eupnoi across all subfamilies as well as in nemastomatid (and at least one ischyropsal…

2017

The endosymbiotic bacterium Wolbachia is the most widespread bacteria in insects, yet the ecology of novel acquisitions in natural host populations is poorly understood. Using temporal data separated by 12 years, I tested the hypothesis that immigration of a parasitoid wasp led to transmission of its Wolbachia strain to its dipteran host, resulting in double-strain infection, and I used geographic and community surveys to explore the history of transmission in fly and parasitoid. Double infection in the fly host was present before immigration of the parasitoid. Equal prevalence of double infection in males and females, constant prevalence before and after immigration in two regions, and inc…

Evolutionary rescue at different rates of environmental change is affected by trade-offs between short-term performance and long-term survival.

2021

As climate change accelerates and habitats free from anthropogenic impacts diminish, populations are forced to migrate or to adapt quickly. Evolutionary rescue (ER) is a phenomenon, in which a population is able to avoid extinction through adaptation. ER is considered to be more likely at slower rates of environmental change. However, the effects of correlated characters on evolutionary rescue are seldom explored yet correlated characters could play a major role in ER. We tested how evolutionary background in different fluctuating environments and the rate of environmental change affect the probability of ER by exposing populations of the bacteria Serratia marcescens to two different rates …