scholarly journals Genetic consequences of in situ and ex situ conservation of forest trees

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.

2015 ◽  
pp. 63-82 ◽  
Author(s):  
Zoran Maksimovic ◽  
Mirjana Sijacic-Nikolic ◽  
Predrag Aleksic ◽  
Ljiljana Sovilj

This paper presents the results of an analysis of the existing seed sources managed by SE ?Srbijasume?. A proposal has been given for new seed sources to be designated in forest areas. This paper highlights the significance of seed sources as a form of in situ conservation, as well as the necessity of establishing seed orchards as a form of ex situ conservation of forest genetic resources, which improves the mass production of reproductive material of forest trees characterized by good genetic quality.


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.


2000 ◽  
Vol 14 (2) ◽  
pp. 382-385 ◽  
Author(s):  
L. M. Clayton ◽  
E. J. Milner‐Gulland ◽  
D. W. Sinaga ◽  
A. H. Mustari

2000 ◽  
Vol 76 (5) ◽  
pp. 765-774 ◽  
Author(s):  
Ken McIlwrick ◽  
S. Wetzel ◽  
T. Beardmore ◽  
K. Forbes

Two tree species native to North America, American chestnut (Castanea dentata (Marsh.) Borkh.) and butternut (Juglans cinerea L.), which have experienced rapid declines in their populations due to similar stressors (disease and changes in land use), are used as examples of how these species would benefit from ex situ conservation efforts. Current and past ex situ and in situ conservation efforts for these species are discussed and the focus of this review is on two key research areas: 1) what needs to be preserved (genetic information) and 2) how to preserve these trees or germplasm. Key words: butternut, American chestnut, Cryphonectria parasitica, Sirococcus clavigignenti-juglandacearum, ex situ conservation


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.


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.


Diversity ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 315 ◽  
Author(s):  
Carlos Mestanza-Ramón ◽  
Sujan M. Henkanaththegedara ◽  
Paola Vásconez Duchicela ◽  
Yadira Vargas Tierras ◽  
Maritza Sánchez Capa ◽  
...  

Biodiversity is vital for the stability of the planet; its ecosystem services provide essential elements for our survival and well-being. This review analyzes the national biodiversity policies and describes the main strategies for biodiversity conservation in Ecuador, one of the “mega-diverse” countries in the world with the highest species density. It deepens an analysis of in-situ and ex-situ conservation processes. Ecuador has six clear policies for biodiversity conservation. These policies strengthen biodiversity conservation through mechanisms that improve the well-being of wildlife by ensuring human, wildlife and ecosystem health. It promotes actions for the welfare of wildlife, through technical, administrative and legal tools. The National System of Protected Areas, with 60 protected areas, is the most effective in-situ conservation instrument at the country level. Several ex-situ conservation and management means for the conservation of wild species are being utilized, including nurseries, botanical gardens, zoos, germplasm banks, aquariums, species reproduction and rehabilitation centers. Ecuador is making slow progress on ex-situ conservation despite the availability of a sound policy framework, possibly due to financial, infrastructural, and/or technological challenges, and knowledge gaps. We propose fostering international research collaborations and establishing fully funded small-scale captive breeding programs at zoos, aquariums and university research facilities to help recovery of at-risk species of reptiles, amphibians, fish and species beyond Galapagos region. We recommend utilizing citizen science programs to fill the gaps of biodiversity information and increasing efforts to revive the ex-situ conservation strategies in protecting the unique biodiversity of Ecuador.


Oryx ◽  
2011 ◽  
Vol 46 (1) ◽  
pp. 18-23 ◽  
Author(s):  
Diana J. Pritchard ◽  
John E. Fa ◽  
Sara Oldfield ◽  
Stuart R. Harrop

AbstractIn situ conservation is central to contemporary global biodiversity protection and is the predominant emphasis of international regulation and funding strategies. Ex situ approaches, in contrast, have been relegated to a subsidiary role and their direct contributions to conservation have been limited. We draw on a variety of sources to make the case for an enhanced role for ex situ conservation. We note the advances occurring within institutions specializing in ex situ conservation and stress that, although much remains to be done, many constraints are being addressed. We argue that the evidence of increasing extinction rates, exacerbated by climate change, challenges the wisdom of a heavy dependence on in situ strategies and necessitates increased development of ex situ approaches. A number of different techniques that enable species and their habitats to survive should now be explored. These could build on the experience of management systems that have already demonstrated the effective integration of in situ and ex situ techniques and hybrid approaches. For organizations specializing in ex situ conservation to become more effective, however, they will require tangible support from the institutions of global biodiversity governance. Resistance is anticipated because in situ conservation is entrenched through powerful groups and organizations that exert influence on global conservation policy and facilitate the flow of funding. The chasm that has traditionally divided in situ and ex situ approaches may diminish as approaches are combined. Moreover, the relentless loss of the ‘wild’ may soon render the in situ / ex situ distinction misleading, or even obsolete.


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.


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