No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Biotic diversity and germplasm preservation: global imperatives
... Contradictory assessments on the state of native-crop loss have been offered in recent studies (Brush 1986, 1989; Wilkes 1989). The recently growing debate contrasts sharply with notable unanimity in the prognosis of a "genetic wipe-out" which had been delivered during the two decades since several scientists and agronomic institutions first expressed concern for the fate of agricultural biodiversity. ...
... Only slightly earlier and in a landmark volume, O.H. Frankel had warned that "primitive cultivars .., are a vanished or vanishing asset" (Frankel 1970: 474). Many current analyses of agricultural biodiversity continue to paint a picture of cultivar loss so complete that it stretches in an even and uninterrupted fashion across the broad canvas which is framed by both diverse crops and geographic regions (Wilkes 1989). Other recent inquiries, on the other hand, have challenged the assumed evenness of native-crop extinction and drawn attention to certain regions of mountain agriculture as possible havens for crop-genetic resources. ...
... Although evocative and widely recognized, the term genetic erosion has been applied to a broad array of processes involving %.. the loss of genes from a gene pool due to the elimination of populations" (Plucknett et al. 1987). (A similarly expansive definition has identified genetic erosion as "... the gradual persistent loss of plant genetic resources .. "' [Wilkes 1989: 181). Hence genetic erosion as currently used refers to a wide variety of biological changes including the loss of genetic material as a result of storage (Frankel and Bennett 1970), breeding procedures (Harlan 1972), and agricultural change in peasant societies (Hawkes 1983). ...
The fate of agricultural biodiversity varies among the native crops produced in a mountainous region. Four native crops (potatoes, maize, ulluco, quinoa) cultivated in the southern Peruvian sierra demonstrate different patterns of cultivar loss and cultivar maintenance. Contingent social, economic and environmental conditions in mountain agriculture shape the distinct fates befalling the cultivars in each crop. Three sets of specific conditions contribute to differences in the patterning of cultivar loss and maintenance: (1) proximate conditions in the local peasant economy, particularly access among agricultural households to land, labor, and capital, and changes in the availability and quality of the three endowments; (2) the social and cultural value of the crop in the local diet and cuisine; and (3) the biogeographic patterning of cultivars. Maintenance of cultivars currently marks the ulluco and quinoa crop as well as many potato and maize types. Cultivar loss besets the fast-maturing potato S. phureja and the slow-maturing maize types. To incorporate variable in situ crop-conservation programs into development planning for montane regions requires thoroughly assessing the contingent conditions for continued production.
... Unfortunately, these supplements are often not fed due to their unavailability and high costs (Nouala et al., 2006). Additionally, as the world population increases relative to arable land, an increased demand for cereal grains and oilseed meals for direct use in human diets is expected in the long run (Knutson and Stoner, 2012). However, less conventional by-products have become available, such as vegetableand fruit-processing residues, whey and culinary wastes (Mirzaei-Aghsaghali and Maheri-Sis, 2008). ...
... In the future, it will be useful to enlarge the dataset to include additional accessions from the collections considered here as well as other European collections [11,31] or collections from other regions worldwide [32][33][34] to provide a wider perspective on genetic resource conservation of apple worldwide. are involved: i) vegetative propagation methods that have been adopted since ancient times favoring the dispersal of cultivars across geographic regions [38,39], ii) forced allogamy due to the self-incompatibility system of Malus × domestica [40], iii) multiple hybridization events at each geographical region combined with human activities, e.g., selection and breeding [36,37] and, iv) diversifying selection associated with adaptive criteria for the subsistence in diverse agricultural environments [41,42]. Interestingly, the distribution of private SSR alleles over the countries of origin of the unique genotypes was somewhat unbalanced at the European level with much higher occurrences in genotypes assigned to Switzerland, Italy or Russia than in genotypes originating from Northern-Western Europe. ...
Background
The amount and structure of genetic diversity in dessert apple germplasm conserved at a European level is mostly unknown, since all diversity studies conducted in Europe until now have been performed on regional or national collections. Here, we applied a common set of 16 SSR markers to genotype more than 2,400 accessions across 14 collections representing three broad European geographic regions (North + East, West and South) with the aim to analyze the extent, distribution and structure of variation in the apple genetic resources in Europe.
Results
A Bayesian model-based clustering approach showed that diversity was organized in three groups, although these were only moderately differentiated (FST = 0.031). A nested Bayesian clustering approach allowed identification of subgroups which revealed internal patterns of substructure within the groups, allowing a finer delineation of the variation into eight subgroups (FST = 0.044). The first level of stratification revealed an asymmetric division of the germplasm among the three groups, and a clear association was found with the geographical regions of origin of the cultivars. The substructure revealed clear partitioning of genetic groups among countries, but also interesting associations between subgroups and breeding purposes of recent cultivars or particular usage such as cider production. Additional parentage analyses allowed us to identify both putative parents of more than 40 old and/or local cultivars giving interesting insights in the pedigree of some emblematic cultivars.
Conclusions
The variation found at group and subgroup levels may reflect a combination of historical processes of migration/selection and adaptive factors to diverse agricultural environments that, together with genetic drift, have resulted in extensive genetic variation but limited population structure. The European dessert apple germplasm represents an important source of genetic diversity with a strong historical and patrimonial value. The present work thus constitutes a decisive step in the field of conservation genetics. Moreover, the obtained data can be used for defining a European apple core collection useful for further identification of genomic regions associated with commercially important horticultural traits in apple through genome-wide association studies.
Electronic supplementary material
The online version of this article (doi:10.1186/s12870-016-0818-0) contains supplementary material, which is available to authorized users.
... Germoplasma (FAO, 2011), las cuales establecen un contenido de humedad óptimo entre el 3 y 7%, dependiendo de las especies (Rincón del vago, 2011), procediendo a su almacenamiento (Cromarty et al., 1985; Towil y Roos, 1989; Cárdenas y Montes, 1992; Gold et al., 2004) de la siguiente manera: Otros factores ambientales distintos de la temperatura y la humedad tienen poca influencia en la conservación de las semillas. Sin embargo, es conveniente que las cámaras de conservación se mantengan en la obscuridad y más si se utilizan recipientes transparentes para el almacenamiento de las semillas (Rincón del vago, 2011). ...
SE DESCRIBE LA METODOLOGÍA PARA LA RECOLECTA, IDENTIFICACIÓN DE PASAPORTE, TRANSPORTE ADECUADO, CONSERVACION Y ESTBLECIMIENTO DE GERMOPLASMA DE ESPECIES FORRAJERAS; LO ANTERIOR, CON FINES DE CONSERVACIÓN Ex situ Y PARA EVALUACIÓN DE ATRIBUTOS FORRAJEROS EN LA MISMA
... Furthermore, provenances for transfer of seeds or seedlings should be delineated based on the significant genetic differentiation among populations. Multiple breeding strategies (Namkoong, 1989), which are well-suited approaches for allogamous tree species like teak with large distribution range, should be implemented in order to conserve and utilize all broad bases of genetic resources sustainably. ...
Teak (Tectona grandis) is a valuable tropical forest tree species which naturally occurs in India, Laos, Myanmar and Thailand. Ten polymorphic nuclear microsatellite markers (SSRs) and seventy-one AFLP markers (Amplified Fragment Length Polymorphisms) were used to investigate genetic variation of teak in natural populations in Myanmar for conservation and sustainable utilization of genetic resources. Adult trees and young regeneration were sampled in selectively logged and unlogged populations in four regions, each in the Northern and Southern parts of Myanmar, and two plantations in Benin. A total of 1667 samples and 1573 samples were used for SSRs and AFLPs, respectively. In general, genetic diversity within teak populations was relatively high but not significantly different between management types and between regeneration and adults. Myanmar populations were less diverse than Benin populations with SSR markers and the allelic richness was significantly higher in Southern than in Northern populations of Myanmar. Additionally, inbreeding was significantly higher in the regeneration in unlogged than in selectively-logged populations. AFLP markers showed contrasting patterns as the Myanmar populations were diverse than those of Benin, and genetic diversity in Northern populations was significantly higher than in the South of Myanmar. Furthermore, genetic diversity of adult trees was significantly higher than in the teak regeneration in unlogged populations. For both markers, cluster and structure analyses revealed two major clusters: one with northern populations and another one with southern populations of Myanmar and those of Benin. A Mantel test showed significant positive correlation between genetic and geographical distances among populations. Analyses of Molecular Variance (AMOVA) detected the highest genetic variation within populations. The FST values were significantly different among all teak populations and higher between than within the regions in Myanmar. This study suggests applying different conservation strategies for Northern and Southern Myanmar.
... loss of variability associated with missing of low frequency alleles (<1%) during repeated regeneration (e.g., Wilkes, 1989; Adugna et al. 2013), the major difference in the diversity of the present study and Cuevas and Prom (2013) was perhaps in the sampling strategy including the sampling area and period. Sorghum grows almost everywhere in Ethiopia between altitude range of 500 and 2400 m. ...
Genetic diversity is a fundamental input for every plant breeding program, genetic resources conservation, and evolutionary studies. In situ diversity and population genetic structure of eight cultivated sorghum landrace populations were investigated in the center of origin, Ethiopia using seven phenotypic traits and 12 highly polymorphic sorghum SSR markers. In farmers’ fields, DNA samples were collected using Whatman® plant saver card and quantitative phenotypic traits were measured from 160 individual plant samples belonging to the eight populations representing three diverse geographical regions. High diversity was observed among the various populations for the measured phenotypic traits. The 12 SSR loci produced a total of 123 alleles of which 78 (63.41%) were rare (frequency ≤0.05) with an average of 10.25 alleles per polymorphic locus. The polymorphism information content (PIC) was in the range 0.39-0.85 showing the good discriminatory power of the SSR loci used. Average observed heterozygosity and gene diversity across all populations and loci ranged 0.04-0.33 and 0.41-0.87, respectively. Neighbor-joining and STRUCTURE analyses grouped the 160 samples from the eight populations differently. AMOVA showed 54.44% of the variation to be within populations, 32.76% among populations within regions, and 12.8% among the regions of origin. There was high divergence in the total populations (FST = 0.40) indicating low level of gene flow (Nm = 0.38), but high gene flow was also observed in some adjacent populations. The populations from Wello displayed close relationship with remote Gibe and Metekel populations indicating that the variation followed human migration patterns. Implications of the results for sorghum improvement and germplasm conservation are discussed.
Electronic supplementary material
The online version of this article (doi:10.1186/2193-1801-3-212) contains supplementary material, which is available to authorized users.
Using morphological characteristics and simple sequence repeat (SSR) markers, we evaluated the morphological variation and genetic diversity of 200 Perilla accessions collected from the five regions of South Korea and another region. In morphological characteristics analysis, particularly leaf color, stem color, degree of pubescence, and leaf size have been found to help distinguish the morphological features of native Perilla accessions cultivated in South Korea. Twenty SSR primer sets confirmed a total of 137 alleles in the 200 Perilla accessions. The number of alleles per locus ranged from 3 to 13, with an average number of alleles per locus of 6.85. The average genetic diversity (GD) was 0.649, with a range of 0.290-0.828. From analysis of SSR markers, accessions from the Jeolla-do and Gyeongsang-do regions showed comparatively high genetic diversity values compared with those from other regions in South Korea. In the unweighted pair group method with arithmetic mean (UPGMA) analysis, the 200 Perilla accessions were found to cluster into three main groups and an outgroup with 42% genetic similarity, and did not show a clear geographic structure from the five regions of South Korea. Therefore, it is believed that landrace Perilla seeds are frequently exchanged by farmers through various routes between the five regions of South Korea. The results of this study are expected to provide interesting information on the conservation of these genetic resources and selection of useful resources for the development of varieties for seeds and leafy vegetables of cultivated Perilla frutescens var. frutescens in South Korea.
Comprehensive protection of genetic resources must be implemented in response to scientific strategies based on our increasing understanding of the complexity of species biology. Without sound scientific approaches to conservation, organizational strategies will fall short of ensuring the protection of the very species they were established to protect. Sound scientific strategies are needed to guide conservation efforts from germplasm acquisition to management of collections at the national and international levels. This will necessitate integrated approaches to comprehensively protect the genetic library represented by global plant genetic resources, including greater interaction between scientists working at the three levels of biological diversity: genetic, species, and ecosystem. Of the three levels which comprise global biological diversity, genetic diversity has received the greatest attention within the agricultural community. Genetic diversity refers to the total genetic information contained in individual plants of a species, each containing a unique assembly of genes constituting its evolutionary heritage. This diversity begins at the molecular level, is carried as sequences of instructions on chromosomes, and provides a foundation for environmental adaptation and ultimately for the evolution of species. This focus on genetic diversity and its application to modem crop improvement allows for manipulation of genetic diversity within time (Duvick, 1984). However, a focus on genetic diversity and ex situ collections alone is not adequate for the needs of global agriculture. For conservation of genetic resources to maintain its relevancy, greater understanding of the remaining two elements of global biodiversity, that of species and ecosystem diversity, will be needed. These components offer the potential for diversity in place as opposed to time. The need for integrated conservation strategies can lead to confusion regarding the types of conservation approaches available, largely because the term' genebank' has come to be equated with the refrigerated seed store. Ex situ samples may be conserved as seed, cultured cells or tissue, or growing plants. In situ may involve a target species as a component of an ecosystem without genetic management or a specific genetic reserve with management intervention. Integrated conservation considers a range of conservation resources and methods for use, depending on the type of genepool, or biological entity of concern (Falk, 1990). In the case of crop plants, which have immediate utility, most are amenable to seed storage. Some require complementary in vitro conservation, and with others, orchards are used as field genebanks. Not all are suitable for long-term storage. An additional responsibility rests with the international community to ensure that national programs relate to international interests based on commodities. Collections maintained by commodity-based International Agricultural Research Centers (lARCs) represent the latter, whereas national collections represent a spectrum of diverse activities related variously to plant introduction, local conservation, and plant breeding. Some are large, integrated, mUlti-crop programs, e.g., in India, China, Brazil, Russia, and USA; others are related to very few crops; and others are solely collections of plant introductions. The Food and Agriculture Organization of the United Nations (F AO) Commission on Plant Genetic Resources presents one means to re-frame national program aims, assure operating funds, and provide global linkages. Many programs will be viable into the future; others may fail, so the security of collections, long a strategic aim of the International Board for Plant Genetic Resources (lBPGR)
n the last decade of the 19th century, North Americans re%ognized the need to protect and rehabitate their fisheries resources. Initial efforts were directed tawards the Great Lakes, because the 10 000 commercial fishermen operating on these lakes (Smith et d. f 887) organized m effective political lobby in response to the precipitous decline in native fish stocks. The fist international conference on fisheries of the Great Lakes was held in 1891 (MacCallum 11892), and at this meeting two solutions to the collapse of the fishery were proposed - the search for new species which might be introduced, and the establishment of hatcheries to enhance populations of native species.
The world-wide capacity of genebanks for ex situ conservation of crop genetic resources has increased greatly since the 1970s, improving the access of crop breeders to landraces and wild and weedy relatives. But utilization of genebank resources has not kept pace. The set of popular cultivars in major crops is typically rather small, and their ancestry encompasses only a fraction of the genetic diversity currently available in other cultivars. Discussions of farmers' rights that focus on compensation for current incorporation of farmers' varieties in new cultivars have diverted attention from the question of why so little of the newly accessible genetic diversity is currently being utilized by public and private breeders. To optimize the future provision of genebank services, research is needed on the costs of genebanks, the market for their services, the use of genetic resources by breeders, and the implications of recognition of farmers' rights, evolving intellectual property rights, continued funding problems and developments in biotechnology.
To feed a world population growing by up to 160 people per minute, with >90% of them in developing countries, will require an astonishing increase in food production. Forecasts call for wheat to become the most important cereal in the world, with maize close behind; together, these crops will account for approximately 80% of developing countries' cereal import requirements. Access to a range of genetic diversity is critical to the success of breeding programs. The global effort to assemble, document, and utilize these resources is enormous, and the genetic diversity in the collections is critical to the world's fight against hunger. The introgression of genes that reduced plant height and increased disease and viral resistance in wheat provided the foundation for the "Green Revolution" and demonstrated the tremendous impact that genetic resources can have on production. Wheat hybrids and synthetics may provide the yield increases needed in the future. A wild relative of maize, Tripsacum, represents an untapped genetic resource for abiotic and biotic stress resistance and for apomixis, a trait that could provide developing world farmers access to hybrid technology. Ownership of genetic resources and genes must be resolved to ensure global access to these critical resources. The application of molecular and genetic engineering technologies enhances the use of genetic resources. The effective and complementary use of all of our technological tools and resources will be required for meeting the challenge posed by the world's expanding demand for food.
ResearchGate has not been able to resolve any references for this publication.