47 research outputs found

    Predictive characterization of crop wild relatives and landraces: technical guidelines version 1

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    Predictive characterization methods use ecogeographical and climatic data derived from the specific location of a collecting or observation site, to predict characteristics of accessions and populations that can inform conservation and use options. The predictive characterization methods presented in these technical guidelines for crop wild relatives (CWR) and landraces (LR) aim to enhance the use of CWR and LR through identification of sets of accessions or occurrences that have a higher likelihood of harbouring genetic diversity for specific adaptive traits than a set selected at random. The methods presented are the ecogeographical filtering and the calibration method. These are two of the various methods that implement the Focused Identification of Germplasm Strategy (FIGS). The guidelines were developed within the framework of the EU funded project PGR Secure ‘Novel characterization of crop wild relative and landrace resources as a basis for improved crop breeding’

    Creation and Validation of the Spanish Durum Wheat Core Collection.

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    Spanish wheat (Triticum spp.) landraces have a considerable polymorphism, containing many unique alleles, relative to other collections. The existence of a core collection is a favored approach for breeders to efficiently explore novel variation and enhance the use of germplasm. In this study, the Spanish durum wheat (Triticum turgidum L.) core collection (CC) was created using a population structure–based method, grouping accessions by subspecies and allocating the number of genotypes among populations according to the diversity of simple sequence repeat (SSR) markers. The CC of 94 genotypes was established, which accounted for 17% of the accessions in the entire collection. An alternative core collection (CH), with the same number of genotypes per subspecies and maximizing the coverage of SSR alleles, was assembled with the Core Hunter software. The quality of both core collections was compared with a random core collection and evaluated using geographic, agromorphological, and molecular marker data not previously used in the selection of genotypes. Both core collections had a high genetic representativeness, which validated their sampling strategies. Geographic and agromorphological variation, phenotypic correlations, and gliadin alleles of the original collection were more accurately depicted by the CC. Diversity arrays technology (DArT) markers revealed that the CC included genotypes less similar than the CH. Although more SSR alleles were retained by the CH (94%) than by the CC (91%), the results showed that the CC was better than CH for breeding purposes

    Transcriptome sequencing of three Pseudo-nitzschia species reveals comparable gene sets and the presence of Nitric Oxide Synthase genes in diatoms

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    Diatoms are among the most diverse eukaryotic microorganisms on Earth, they are responsible for a large fraction of primary production in the oceans and can be found in different habitats. Pseudo-nitzschia are marine planktonic diatoms responsible for blooms in coastal and oceanic waters. We analyzed the transcriptome of three species, Pseudo-nitzschia arenysensis, Pseudo-nitzschia delicatissima and Pseudo-nitzschia multistriata, with different levels of genetic relatedness. These species have a worldwide distribution and the last one produces the neurotoxin domoic acid. We were able to annotate about 80% of the sequences in each transcriptome and the analysis of the relative functional annotations allowed comparison of the main metabolic pathways, pathways involved in the biosynthesis of isoprenoids (MAV and MEP pathways), and pathways putatively involved in domoic acid synthesis. The search for homologous transcripts among the target species and other congeneric species resulted in the discovery of a sequence annotated as Nitric Oxide Synthase (NOS), found uniquely in Pseudo-nitzschia multistriata. The predicted protein product contained all the domains of the canonical metazoan sequence. Putative NOS sequences were found in other available diatom datasets, supporting a role for nitric oxide as signaling molecule in this group of microalgae

    Upward Altitudinal Shifts in Habitat Suitability of Mountain Vipers since the Last Glacial Maximum

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    We determined the effects of past and future climate changes on the distribution of the Montivipera raddei species complex (MRC) that contains rare and endangered viper species limited to Iran, Turkey and Armenia. We also investigated the current distribution of MRC to locate unidentified isolated populations as well as to evaluate the effectiveness of the current network of protected areas for their conservation. Present distribution of MRC was modeled based on ecological variables and model performance was evaluated by field visits. Some individuals at the newly identified populations showed uncommon morphological characteristics. The distribution map of MRC derived through modeling was then compared with the distribution of protected areas in the region. We estimated the effectiveness of the current protected area network to be 10%, which would be sufficient for conserving this group of species, provided adequate management policies and practices are employed. We further modeled the distribution of MRC in the past (21,000 years ago) and under two scenarios in the future (to 2070). These models indicated that climatic changes probably have been responsible for an upward shift in suitable habitats of MRC since the Last Glacial Maximum, leading to isolation of allopatric populations. Distribution will probably become much more restricted in the future as a result of the current rate of global warming. We conclude that climate change most likely played a major role in determining the distribution pattern of MRC, restricting allopatric populations to mountaintops due to habitat alterations. This long-term isolation has facilitated unique local adaptations among MRC populations, which requires further investigation. The suitable habitat patches identified through modeling constitute optimized solutions for inclusion in the network of protected areas in the region

    Conservation Status and Threat Assessments for North American Crop Wild Relatives

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    Conservation status and threat assessments evaluate species’ relative risks of extinction globally, regionally, nationally, or locally and estimate the degree to which populations of species are already safeguarded in existing conservation systems, with the aim of exposing the critical gaps in current conservation. Results of the assessments can therefore aid in directing limited conservation resources to the species and populations that are most at-risk. This chapter introduces the roles of conservation status and threat assessments in informing conservation priorities for crop wild relatives in North America and provides an overview of the current results for US taxa. Methods to assess the conservation status and to perform threat assessments for North American crop wild relatives are well developed via NatureServe and the International Union for Conservation of Nature (IUCN) Red List, and the essential infrastructure to perform these analyses is present, at least in Canada and the US. Current conservation assessments for North American wild relatives need updating but already reveal a landscape of multiple complex threats and major gaps in the ex situ and in situ conservation of prioritized species. Further resources and concerted efforts are needed to update conservation assessments and then to use the results to inform efforts to fill the critical gaps in conservation
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