Application of genetic markers in the domestication, conservation and utilisation of genetic resources of Australasian tree species

2000 ◽  
Vol 48 (3) ◽  
pp. 313 ◽  
Author(s):  
G. F. Moran ◽  
P. A. Butcher ◽  
J. C. Glaubitz
Keyword(s):  
Genetic Diversity ◽  
Molecular Marker ◽  
Genetic Resources ◽  
Tree Species ◽  
Acacia Mangium ◽  
Ex Situ ◽  
Conservation Strategies ◽  
Breeding Programs ◽  
Native Forests ◽  
The Impact

Domestication programs are currently being developed for a number of Australasian tropical tree species for plantations largely outside Australia. An assessment of the genetic resources of several species has been made on the basis of levels and patterns of genetic diversity at molecular marker loci. On the basis of growth performance and other quantitatively inherited commercial traits, populations from only limited regions of the geographic range were included in baseline selections of breeding programs for species such as Acacia mangium, A. auriculiformis, A. aulacocarpa and Eucalyptus pellita. For A. mangium, this domestication strategy resulted in a high proportion of the genetic resources of the species being included in breeding programs, but for other species such as A. aulacocarpa a significant fraction of the genetic resources were not incorporated into the baseline populations. The same molecular marker data sets enabled the formulation of conservation strategies both in situ and ex situ for these important commercial species. Within Australia many tree species are utilised directly from native forests in the absence of domestication efforts. Preliminary results from a study on genetic impacts of silvicultural regeneration practices in native forests indicate that there is very limited loss in genetic diversity in E. sieberi, a locally abundant species, under either clearfelling with aerial resowing or the seed tree system. Questions remain concerning the impact of silvicultural regeneration practices on species that are more locally rare.

Key issues facing genebanks in preserving crop genetic diversity ex situ: overview of the range of challenges

2021 ◽  
pp. 139-154
Author(s):  
Paula Bramel ◽  
Keyword(s):  
Genetic Diversity ◽  
Genetic Resources ◽  
Plant Genetic Resources ◽  
Cost Effective ◽  
Ex Situ ◽  
Crop Genetic Diversity ◽  
Ex Situ Collections ◽  
Key Issues ◽  
Market Preference ◽  
The Impact

This chapter reviews the key issues and challenges facing genebanks in preserving crop genetic diversity ex situ. Local crop genetic diversity is challenged with changes in land use, urbanization, land degradation, changes in agricultural practises, availability of improved varieties, changes in market preference, and the impact of climate change. Efforts have been made to secure plant genetic resources ex situ for future use but there are significant issues related to cost effective, efficient, secure, rational, and sustainable long-term ex situ conservation. It begins by addressing issues for the composition of ex situ collections and moves on to discuss issues for routine operations for conservation. The chapter also highlights issues for the use of conserved genetic resources, before concluding with a summary of why the development of sustainable genebank systems is so important.

scholarly journals Genetic variability and population structure of Ethiopian chickpea (Cicer arietinum L.) germplasm

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0260651
Author(s):  
Sintayehu Admas ◽  
Kassahun Tesfaye ◽  
Teklehaimanot Haileselassie ◽  
Eleni Shiferaw ◽  
K. Colton Flynn
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Ssr Markers ◽  
Polymorphic Information Content ◽  
Germplasm Conservation ◽  
Genetic Distances ◽  
Geographic Region ◽  
Ex Situ ◽  
Conservation Strategies ◽  
Breeding Programs

Evaluation of the genetic diversity and an understanding of the genetic structure and relationships of chickpea genotypes are valuable to design efficient germplasm conservation strategies and crop breeding programs. Information is limited, in these regards, for Ethiopian chickpea germplasms. Therefore, the present study was carried out to estimate the genetic diversity, population structure, and relationships of 152 chickpea genotypes using simple sequence repeats (SSR) markers. Twenty three SSR markers exhibited polymorphism producing a total of 133 alleles, with a mean of 5.8 alleles per locus. Analyses utilizing various genetic-based statistics included pairwise population Nei’s genetic distance, heterozygosity, Shannon’s information index, polymorphic information content, and percent polymorphism. These analyses exemplified the existence of high genetic variation within and among chickpea genotypes. The 152 genotypes were divided into two major clusters based on Nei’s genetic distances. The exotic genotypes were grouped in one cluster exclusively showing that these genotypes are distinct to Ethiopian genotypes, while the patterns of clustering of Ethiopian chickpea genotypes based on their geographic region were not consistent because of the seed exchange across regions. Model-based population structure clustering identified two discrete populations. These finding provides useful insight for chickpea collections and ex-situ conservation and national breeding programs for widening the genetic base of chickpea.

scholarly journals Genetic Diversity and Population Structure Analysis of Dalbergia Odorifera Germplasm and Development of a Core Collection Using Microsatellite Markers

Genes ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 281 ◽  
Author(s):  
Fu-Mei Liu ◽  
Ning-Nan Zhang ◽  
Xiao-Jin Liu ◽  
Zeng-Jiang Yang ◽  
Hong-Yan Jia ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Microsatellite Markers ◽  
Genetic Resources ◽  
Tree Species ◽  
Core Collection ◽  
Southern China ◽  
Breeding Programs ◽  
Expected Heterozygosity ◽  
Dalbergia Odorifera

Dalbergia odorifera T. Chen (Fabaceae) is a woody tree species indigenous to Hainan Island in China. Due to its high medicinal and commercial value, this tree species has been planted over 3500 ha2 in southern China. There is an urgent need for improvement of the D. odorifera germplasm, however, limited information on germplasm collection, conservation, and assessment of genetic resources is available. Therefore, we have built a database of 251 individuals collected across the whole of southern China, which included 42 wild trees and 210 cultivated trees, with the following objectives. (1) Evaluate genetic diversity and population structure of the database using 19 microsatellite markers and (2) develop a core collection for improvement and breeding programs. Totally, the 19 microsatellite markers harbored 77 alleles across the database with the polymorphic information content (PIC) ranging from 0.03 to 0.66. Medium genetic diversity level was inferred by Nei’s gene diversity (0.38), Shannon’s information index (0.65), and observed (0.33) and expected heterozygosity (0.38). Structure analysis showed that four was the optimum cluster size using the model-based Bayesian procedure, and the 251 D. odorifera individuals were grouped into five populations including four pure ones (RP1-4) and one mixed one (MIX) based on their maximum membership coefficients. Among these populations, the expected heterozygosity varied from 0.30 (RP3) to 0.38 (RP4). Analysis of molecular variance (AMOVA) showed 11% genetic variation existed among populations, and moderate population differentiation was inferred by the matrix of pairwise Fst (genetic differentiation among populations), which was in the range of 0.031 to 0.095. Moreover, a core collection of 31 D. odorifera individuals including six wild and 25 cultivated trees was developed, which was only 12.4% of the database but conserved the whole genetic diversity. The results of this study provided additional insight into the genetic structure of the large D. odorifera germplasm, and the core collection will be useful for the efficient and sustainable utilization of genetic resources, as well as efficient improvement in breeding programs.

Strategies for conservation of germplasm in endemic redwoods in the face of climate change: a review

2011 ◽  
Vol 9 (3) ◽  
pp. 411-422 ◽  
Author(s):  
M. R. Ahuja
Keyword(s):  
Climate Change ◽  
Genetic Diversity ◽  
Conservation Strategy ◽  
Ex Situ ◽  
Conservation Strategies ◽  
Phenotypic Traits ◽  
Coast Redwood ◽  
Giant Sequoia ◽  
The Face

This study reviews the various conservation strategies applied to the four redwood species, namely coast redwood (Sequoia sempervirens), Sierra redwood or giant sequoia (Sequoiadendron giganteum), dawn redwood (Metasequoia glyptostroboides) and South American redwood or alerce (Fitzroya cupressoides), which are endemic in the USA, China and South America, respectively. All four redwood genera belong to the family Cupressaceae; they are monospecific, share a number of common phenotypic traits, including red wood, and are threatened in their native ranges due to human activity and a changing climate. Therefore, the management objective should be to conserve representative populations of the native species with as much genetic diversity as possible for their future survival. Those representative populations exhibiting relatively high levels of genetic diversity should be selected for germplasm preservation and monitored during the conservation phase by using molecular markers. In situ and ex situ strategies for the preservation of germplasm of the redwoods are discussed in this study. A holistic in situ gene conservation strategy calls for the regeneration of a large number of diverse redwood genotypes that exhibit adequate levels of neutral and adaptive genetic variability, by generative and vegetative methods for their preservation and maintenance in their endemic locations. At the same time, it would be desirable to conserve the redwoods in new ex situ reserves, away from their endemic locations with similar as well as different environmental conditions for testing their growth and survival capacities. In addition, other ex situ strategies involving biotechnological approaches for preservation of seeds, tissues, pollen and DNA in genebanks should also be fully exploited in the face of global climate change.

The use of ex situ conserved plant genetic resources

2003 ◽  
Vol 1 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Toby Hodgkin ◽  
V. Ramanatha Rao ◽  
Angélica Cibrian-Jaramillo ◽  
Samy Gaiji
Keyword(s):  
Genetic Diversity ◽  
Genetic Resources ◽  
Agricultural Production ◽  
Production Systems ◽  
Plant Genetic Resources ◽  
Ex Situ ◽  
Recent Information ◽  
Wide Range ◽  
Barriers To Use ◽  
The Many

AbstractPlant genetic resources are conserved so that they can be used to improve crop plant pro- duction and in other ways. However, it is often asserted that use of ex situ conserved germplasm is inadequate and that genetic diversity maintained in genebanks is underutilized. In part, this reflects an incomplete recognition of what constitutes use of plant genetic resources, and of the many different ways in which material from genebanks contributes to improved agricultural production. Based on recent information from surveys of distribution of germplasm from genebanks, and from surveys of users, we suggest that the evidence indicates that there is substantial use of ex situ conserved materials for a wide range of different uses. We suggest that barriers to use of ex situ conserved germplasm may often result from a lack in numbers of users, and from limitations in capacity to effectively utilize the genetic diversity present in genebanks to reduce genetic vulnerability and increase sustainability in modern production systems.

Review of global rabbit genetic resources: special emphasis on breeding programs and practices in the lesser developed countries

1998 ◽  
Vol 23 ◽  
pp. 49-67 ◽  
Author(s):  
S. D. Lukefahr
Keyword(s):  
Genetic Diversity ◽  
Genetic Resources ◽  
Management Practices ◽  
Limited Resource ◽  
Developed Countries ◽  
Breeding Program ◽  
Breeding Programs ◽  
National Priority ◽  
Genetic Resources Management ◽  
Resources Conservation

SummaryPresently, there is little organization or cooperation among countries with rabbit breeding programs with the common aim of maintaining genetic diversity, with the exception of Europe and the Mediterranean region. Particularly in the lesser developed countries (LDC's), there is limited evidence that maintaining genetic diversity in rabbit populations is even a national priority. Based on consultancies and project experiences in over fifteen LDC's, and limited reports from the literature, evaluations of breeding programs at national rabbit breeding centers have generally been less than encouraging with regard to the management of genetic resources: utilization and conservation. The purpose of this position paper is to review rabbit genetic resources management practices and trends in rabbit breeding program development which pertain to genetic resources utilization and conservation issues, and with special emphasis on the LDC's. Several measures are discussed that could enhance breeding program integrity, greater benefit limited-resource farmers, and also foster international and regional participation in rabbit genetic resources conservation programs.

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