scholarly journals Drilling down hotspots of intraspecific diversity to bring them into on-ground conservation of threatened species

2018 ◽  
Author(s):  
Mauro Zampiglia ◽  
Roberta Bisconti ◽  
Luigi Maiorano ◽  
Gaetano Aloise ◽  
Antonino Siclari ◽  
...  

AbstractUnprecedented rates of biodiversity loss rise the urgency for preserving species ability to cope with ongoing global changes. An approach in this direction is to target intra-specific hotspots of genetic diversity as conservation priorities. However, these hotspots are often identified by sampling at a spatial resolution too coarse to be useful in practical management of threatened species, hindering the long-appealed dialog between conservation stakeholders and conservation genetic researchers. Here, we investigated the spatial and temporal variation in species presence, genetic diversity, as well as potential risk factors, within a previously identified hotspot of genetic diversity for the endangered Apennine yellow bellied toad Bombina pachypus. Our results show that this hotspot is neither a geographically homogeneous nor a temporally stable unit. Over a time-window spanning 10-40 years since previous assessments, B. pachypus populations declined in large portions of its hotspot, and their genetic diversity levels decreased. Considering the demographic trend, genetic and epidemiological data, and models of current and future climatic suitability, populations at the extreme south of the hotspot area still qualify for urgent in-situ conservation actions, whereas northern populations would be better managed through a mix of in-situ and ex-situ actions. Our results emphasize that identifying hotspot of genetic diversity, albeit essential step, does not suffice to warrant on-ground conservation of threatened species. Hotspots should be analysed at finer geographic and temporal scales, to provide conservation stakeholders with key knowledge to best define conservation priorities, and to optimize resource allocation to alternative management practices.

2015 ◽  
Author(s):  
Julio Peñas ◽  
Sara Barrios ◽  
Javier Bobo-Pinilla ◽  
Juan Lorite ◽  
M. Montserrat Martínez-Ortega

Astragalus edulis (Fabaceae) is an endangered annual species from western Mediterranean region that colonized SE Iberian Peninsula, NE and SW Morocco, and the easternmost Macaronesian islands (Lanzarote and Fuerteventura). Although in Spain some conservation measures have been adopted, it is still necessary to develop an appropriate management plan to preserve genetic diversity across the entire distribution area of the species. Our main objective was to use population genetics as well as ecological and phylogeographic data to select Relevant Genetic Units for Conservation (RGUCs) as the first step in designing conservation plans for A. edulis. We identified six RGUCs for in situ conservation, based on estimations of population genetic structure and probabilities of the loss of rare alleles. Additionally, further population parameters, i.e. occupation area, population size, vulnerability, legal status of the population areas, and the historical haplotype distribution, were considered in order to establish which populations deserve conservation priority. Three populations from the Iberian Peninsula, two from Morocco, and one from the Canary Islands represent the total genetic diversity of the species and the rarest allelic variation. Ex situ conservation is recommended to complement the preservation of A. edulis, given that effective in situ population protection is not feasible in all cases. The consideration of complementary phylogeographic and ecological data is useful for management efforts to preserve the evolutionary potential of the species.


Author(s):  
Anthony Hitchcock ◽  
Anthony G. Rebelo

The Threatened Species Programme at the South African National Biodiversity Institute, Kirstenbosch National Botanical Garden, is integrated to include both ex situ and in situ conservation activities. Plant conservation is driven by South Africa’s Strategy for Plant Conservation which was developed in response to the Global Strategy for Plant Conservation. This case study examines the conservation of Erica verticillata (whorl heath), a flagship for threatened species at Kirstenbosch, and documents the integration of ex situ with in situ conservation at three areas on the Cape Flats. The whorl heath was thought to be extinct by 1950. Horticulturists have since rediscovered eight clones in botanic gardens worldwide, the Heather Society and commercial growers. Ex situ conservation in botanic garden collections and the Millennium Seed Bank has since allowed in situ conservation in the critically endangered Cape Flats Sand Fynbos vegetation type. The process of restoring the whorl heath presented many challenges. Initially attempts were hampered by limited available knowledge on suitable niche habitats. Pioneering work carried out at Rondevlei Nature Reserve identified the suitable habitat and this was applied in subsequent in situ work at Kenilworth Racecourse Conservation Area and at Tokai Park – the only natural areas remaining in or near this species’ historical distribution range. Successful re-establishment of this species depends upon its capacity to recruit after fire, which is an essential ecological process in the fynbos. Many clones have been in cultivation for a long time and are poor seed producers: seed production was first recorded at Rondevlei only after additional clones were planted together. Only one population (Rondevlei) to date has seen a fire and thus has recruited seedlings; however these are competing with vigorous companion plants. The study continues and is currently exploring the role of herbivory in the restoration process. The key lesson learnt to date is the need to include sustainable management of the entire ecosystem in the restoration process and not limit it to single species. Success in restoring a species depends upon a healthy stand of the vegetation type in place, along with pollinators and other key fauna and other natural ecosystem processes. It is recommended that successful re- establishment of a species in fynbos requires the reintroduced population to survive three fire cycles.


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1474 ◽  
Author(s):  
Julio Peñas ◽  
Sara Barrios ◽  
Javier Bobo-Pinilla ◽  
Juan Lorite ◽  
M. Montserrat Martínez-Ortega

Astragalus edulis(Fabaceae) is an endangered annual species from the western Mediterranean region that colonized the SE Iberian Peninsula, NE and SW Morocco, and the easternmost Macaronesian islands (Lanzarote and Fuerteventura). Although in Spain some conservation measures have been adopted, it is still necessary to develop an appropriate management plan to preserve genetic diversity across the entire distribution area of the species. Our main objective was to use population genetics as well as ecological and phylogeographic data to select Relevant Genetic Units for Conservation (RGUCs) as the first step in designing conservation plans forA. edulis. We identified six RGUCs for in situ conservation, based on estimations of population genetic structure and probabilities of loss of rare alleles. Additionally, further population parameters, i.e. occupation area, population size, vulnerability, legal status of the population areas, and the historical haplotype distribution, were considered in order to establish which populations deserve conservation priority. Three populations from the Iberian Peninsula, two from Morocco, and one from the Canary Islands represent the total genetic diversity of the species and the rarest allelic variation. Ex situ conservation is recommended to complement the preservation ofA. edulis, given that effective in situ population protection is not feasible in all cases. The consideration of complementary phylogeographic and ecological data is useful for management efforts to preserve the evolutionary potential of the species.


Heredity ◽  
2021 ◽  
Author(s):  
Francis Denisse McLean-Rodríguez ◽  
Denise Elston Costich ◽  
Tania Carolina Camacho-Villa ◽  
Mario Enrico Pè ◽  
Matteo Dell’Acqua

AbstractGenomics-based, longitudinal comparisons between ex situ and in situ agrobiodiversity conservation strategies can contribute to a better understanding of their underlying effects. However, landrace designations, ambiguous common names, and gaps in sampling information complicate the identification of matching ex situ and in situ seed lots. Here we report a 50-year longitudinal comparison of the genetic diversity of a set of 13 accessions from the state of Morelos, Mexico, conserved ex situ since 1967 and retrieved in situ from the same donor families in 2017. We interviewed farmer families who donated in situ landraces to understand their germplasm selection criteria. Samples were genotyped by sequencing, producing 74,739 SNPs. Comparing the two sample groups, we show that ex situ and in situ genome-wide diversity was similar. In situ samples had 3.1% fewer SNPs and lower pairwise genetic distances (Fst 0.008–0.113) than ex situ samples (Fst 0.031–0.128), but displayed the same heterozygosity. Despite genome-wide similarities across samples, we could identify several loci under selection when comparing in situ and ex situ seed lots, suggesting ongoing evolution in farmer fields. Eight loci in chromosomes 3, 5, 6, and 10 showed evidence of selection in situ that could be related with farmers’ selection criteria surveyed with focus groups and interviews at the sampling site in 2017, including wider kernels and larger ear size. Our results have implications for ex situ collection resampling strategies and the in situ conservation of threatened landraces.


2020 ◽  
Vol 12 (2) ◽  
pp. 613
Author(s):  
Abdul Rehman Khan ◽  
Isabelle Goldringer ◽  
Mathieu Thomas

As the effects of climate change begin to be felt on yield stability, it is becoming essential to promote the use of genetic diversity in farmers’ fields. The presence of genetic variability in variety could fulfil this purpose. Indeed, the level of intra-varietal genetic diversity influences the spatio-temporal stability of yields and the disease susceptibility of crop species. Breeding history of varieties and their management practices are two factors that should influence intra-varietal genetic diversity. This paper describes the genetic diversity of eight wheat samples covering a gradient from modern single varieties to on-farm mixtures of landraces. This gradient discriminates between landrace, historical and modern varieties, considering the breeding history of varieties, between single-varieties and mixtures of varieties, and between ex situ and in situ de facto strategy in terms of management practices. Genetic diversity of these samples was analyzed with the help of 41 single nucleotide polymorphism markers located in neutral regions, through computing genetic indices at three different levels: Allelic, haplotypic and genetic group level. Population structure and kinship were depicted using discriminant analysis and kinship network analysis. Results revealed an increase in the complexity of the genetic structure as we move on the gradient of variety types (from modern single variety to in situ on-farm mixtures of landraces). For the landraces, the highest levels of genetic diversity have been observed for a landrace (Solina d’Abruzzo) continuously grown on-farm in the region of Abruzzo, in Italy, for many decades. This landrace showed an excess of haplotypic diversity compared to landraces or the historical variety that were stored in genebanks (ex situ conservation). Genetic analyses of the mixtures revealed that, despite a very high selfing rate in wheat, growing in evolutionary mixtures promotes recombination between different genetic components of the mixture, a second way to increase the level of haplotype diversity. When management practices such as growing in mixture and on-farm management are combined, they substantially increase the different levels of genetic diversity of the populations (allelic, haplotypic, genetic group diversity), and consequently promote their adaptability. Our results confirm the need to develop and manage evolving diversified large populations on-farm. These results invite crop diversity managers such as genebank curators, community seed bank managers and farmers’ organizations to adapt their management strategies to the type of variety they wish to manage, because we have shown that their choices have a strong influence on the genetic composition of the crop populations.


Agriculture ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 129 ◽  
Author(s):  
Lothar Frese ◽  
Maria Bönisch ◽  
Marion Nachtigall ◽  
Uta Schirmak

In Germany, the wild ancestor (Apium graveolens L. ssp. graveolens) of celery and celeriac is threatened by genetic erosion. Seventy-eight potentially suitable genetic reserve sites representing differing ecogeographic units were assessed with regard to the conservation status of the populations. At 27 of the 78 sites, 30 individual plants were sampled and genetically analyzed with 16 polymorphic microsatellite makers. The Discriminant Analysis of Principal Components (DAPC) was applied to identify clusters of genetically similar individuals. In most cases (25 out of 27 occurrences) individuals clustered into groups according to their sampling site. Next to three clearly separated occurrences (AgG, AgUW, AgFEH) two large groups of inland and Baltic Sea coast occurrences, respectively, were recognized. Occurrences from the coastal part of the distribution area were interspersed into the group of inland occurrences and vice versa. The genetic distribution pattern is therefore complex. The complementary compositional genetic differentiation Δj was calculated to identify the Most Appropriate Wild Populations (MAWP) for the establishment of genetic reserves. Altogether 15 sites are recommended to form a genetic reserve network. This organisational structure appears suitable for promoting the in situ conservation of intraspecific genetic diversity and the species’ adaptability. As seed samples of each MAWP will be stored in a genebank, the network would likewise contribute to the long-term ex situ conservation of genetic resources for plant breeding.


2015 ◽  
Author(s):  
Julio Peñas ◽  
Sara Barrios ◽  
Javier Bobo-Pinilla ◽  
Juan Lorite ◽  
M. Montserrat Martínez-Ortega

Astragalus edulis (Fabaceae) is an endangered annual species from western Mediterranean region that colonized SE Iberian Peninsula, NE and SW Morocco, and the easternmost Macaronesian islands (Lanzarote and Fuerteventura). Although in Spain some conservation measures have been adopted, it is still necessary to develop an appropriate management plan to preserve genetic diversity across the entire distribution area of the species. Our main objective was to use population genetics as well as ecological and phylogeographic data to select Relevant Genetic Units for Conservation (RGUCs) as the first step in designing conservation plans for A. edulis. We identified six RGUCs for in situ conservation, based on estimations of population genetic structure and probabilities of the loss of rare alleles. Additionally, further population parameters, i.e. occupation area, population size, vulnerability, legal status of the population areas, and the historical haplotype distribution, were considered in order to establish which populations deserve conservation priority. Three populations from the Iberian Peninsula, two from Morocco, and one from the Canary Islands represent the total genetic diversity of the species and the rarest allelic variation. Ex situ conservation is recommended to complement the preservation of A. edulis, given that effective in situ population protection is not feasible in all cases. The consideration of complementary phylogeographic and ecological data is useful for management efforts to preserve the evolutionary potential of the species.


1992 ◽  
Vol 68 (6) ◽  
pp. 720-729 ◽  
Author(s):  
Rong-Cai Yang ◽  
Francis C. Yeh

To counteract loss of genetic diversity crucial for current and future tree improvement, tree breeders have conserved forest genetic resources in situ in their natural ecosystems in protected areas or ex situ in plantations, seed orchards, and breeding arboreta. This article reviews the genetic consequences of these two conservation methods in terms of single-locus and multilocus population structure from electrophoretic studies of natural forests and breeding populations. Although natural forest populations have maintained high level of genetic diversity and exhibited low level of population differentiation, loss of genetic diversity would occur during the entire conservation process, from population establishment to management of breeding and production populations. Since forest trees are still at their earliest stage of domestication in Canada, loss of genetic diversity comes primarily from the initial sampling process during population establishment. We discuss the optimal sampling strategy during population establishment to conserve common and widespread alleles, common and localized alleles, rare and widespread alleles, and rare and localized alleles. We also discuss three methods for studying the multilocus structure of forest trees and show how such information would be useful for conserving co-adapted gene complexes. We conclude that being small and maintained in controlled environments, ex situ conserved populations would retain less genetic diversity than in situ conserved forest populations. While ex situ conservation is operationally convenient for the short-term gains in tree improvement, we believe in situ conservation is essential for renewing the genetic diversity to meet the changing environments of an uncertain future.


Oryx ◽  
2018 ◽  
Vol 54 (1) ◽  
pp. 125-132 ◽  
Author(s):  
Kevin Johnson ◽  
Anne Baker ◽  
Kevin Buley ◽  
Luis Carrillo ◽  
Richard Gibson ◽  
...  

AbstractConservation resources are limited, yet an increasing number of species are under threat. Assessing species for their conservation needs is, therefore, a vital first step in identifying and prioritizing species for both ex situ and in situ conservation actions. Using a transparent, logical and objective method, the Conservation Needs Assessment process developed by Amphibian Ark uses current knowledge of species in the wild to determine those with the most pressing conservation needs, and provides a foundation for the development of holistic conservation action plans that combine in situ and ex situ actions as appropriate. These assessments allow us to maximize the impact of limited conservation resources by identifying which measures could best serve those species requiring help. The Conservation Needs Assessment complements the IUCN Red List assessment, and together they provide a more holistic guide to conservation priorities and actions. Conservation Needs Assessments generate national prioritized lists of species recommended for conservation action. These can subsequently be used to assist in the development of species recovery plans and national action plans, or to inform national conservation priorities better. Additional tools that will evaluate the recommendations for ex situ rescues, to determine the best candidates for conservation breeding programmes, are currently under development.


Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 638
Author(s):  
Marcelo B. Medeiros ◽  
José F. M. Valls ◽  
Aluana G. Abreu ◽  
Gustavo Heiden ◽  
Suelma Ribeiro-Silva ◽  
...  

This study presents the status of ex situ and in situ conservation for the crop wild relatives of rice, potato, sweet potato, and finger millet in Brazil, and the subsequent germplasm collection expeditions. This research is part of a global initiative entitled “Adapting Agriculture to Climate Change: Collecting, Protecting, and Preparing Crop Wild Relatives” supported by the Global Crop Diversity Trust. Species of the primary, secondary, and tertiary gene pools with occurrences reported in Brazil were included: Oryza alta Swallen, O. grandiglumis (Döll) Prod., O. latifolia Desv., O. glumaepatula Steud., Eleusine tristachya (Lam.) Lam., E. indica (L.) Gaertn., Solanum commersonii Dunal, S. chacoense Bitter, Ipomoea grandifolia (Dammer) O’Donell, I. ramosissima (Poir.) Choisy, I. tiliacea (Willd.) Choisy, I. triloba L., and I. cynanchifolia Meisn. The status of the ex situ and in situ conservation of each taxon was assessed using the gap analysis methodology, and the results were used to plan 16 germplasm collection expeditions. Seeds of the collected material were evaluated for viability, and the protocols for seed germination and cryopreservation were tested. The final conservation score, resulting from the gap analysis and including the average of the ex situ and in situ scores, resulted in a classification of medium priority of conservation for all the species, with the exception of I. grandifolia (high priority). The total accessions collected (174) almost doubled the total accessions of these crop wild relatives incorporated in Embrapa’s ex situ conservation system prior to 2015. In addition, accessions for practically absent species were collected for the ex situ conservation system, such as Ipomoea species, Eleusine indica, and Solanum chacoense. The methods used for dormancy breaking and low temperature conservation for the Oryza, Eleusine, and Ipomoea species were promising for the incorporation of accessions in the respective gene banks. The results show the importance of efforts to collect and conserve ex situ crop wild relatives in Brazil based on previous gap analysis. The complementarity with the in situ strategy also appears to be very promising in the country.


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