Zur Technik der Sortimentserhaltung

Lehmann, Chr O.; Mansfeld, R.

doi:10.1007/bf02095492

Cited by 30 publications

(9 citation statements)

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“…Bulking means in this context creating phenotypically homogeneous, but potentially genetically still heterogeneous bulk-accessions. The strategy could be described as ''phenotypical homogenization of accessions'', which can be the result of separating accessions as suggested by Lehmann and Mansfeld (1957) or of bulking of phenotypically identical duplicates.…”

Section: Discussionmentioning

confidence: 99%

Duplication assessments in Nordic Avena sativa accessions at the Canadian national genebank

Diederichsen

2008

Genet Resour Crop Evol

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This study applied two methods to assess intra-collection duplication within 339 Nordic oat (Avena sativa L.) accessions preserved by Plant Gene Resources of Canada (PGRC). Putative duplicates, that is accessions carrying a similar accession name, were grouped into 52 duplication groups and included 230 of the 339 Nordic oat accessions. A field assessment based on visual inspection of field plots was conducted during two growing seasons to detect distinct phenotypes within each duplication group. Simultaneously, a descriptor assessment using seven characters with altogether sixteen character states was used in both years for the same purpose. The combined results of both assessments and both years indicated that among the 230 accessions in duplication groups only 118 could be identified as distinct. This would allow for a reduction of 33% of the Nordic oat accessions at PGRC. The field assessment method detected fewer (75%) distinct accessions than the descriptor assessment (84%), when considering all accessions identified as distinct as 100%. Repeatability between years was higher in the field assessment (70%) than in the descriptor assessment (64%). The field assessment requires an experienced germplasm evaluator, but allows for handling large numbers of germplasm accessions and for detecting functional, fitness related, and user-relevant diversity. Combining field assessment with descriptor assessment and more sophisticated methods on selected subgroups may be the most efficient method for determination of internal duplication in genebank collections. Bulking phenotypically similar accessions within duplication groups is preferable to eliminating duplicate accessions when collection rationalization is required, as it reduces the risk of loosing diversity.

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Section: Discussionmentioning

confidence: 99%

Duplication assessments in Nordic Avena sativa accessions at the Canadian national genebank

Diederichsen

2008

Genet Resour Crop Evol

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“…The IPK genebank practices the splitting of original landrace accessions and maintains them as morphologically distinct accessions to counteract the possible loss of rare alleles in the original population of genotypes [42] , [43] . For this reason, a current landrace accession might correspond to a single representative genotype of the original landrace population collected.…”

Section: Methodsmentioning

confidence: 99%

Genetic Diversity and Population Structure in a Legacy Collection of Spring Barley Landraces Adapted to a Wide Range of Climates

et al. 2014

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Global environmental change and increasing human population emphasize the urgent need for higher yielding and better adapted crop plants. One strategy to achieve this aim is to exploit the wealth of so called landraces of crop species, representing diverse traditional domesticated populations of locally adapted genotypes. In this study, we investigated a comprehensive set of 1485 spring barley landraces (Lrc1485) adapted to a wide range of climates, which were selected from one of the largest genebanks worldwide. The landraces originated from 5° to 62.5° N and 16° to 71° E. The whole collection was genotyped using 42 SSR markers to assess the genetic diversity and population structure. With an average allelic richness of 5.74 and 372 alleles, Lrc1485 harbours considerably more genetic diversity than the most polymorphic current GWAS panel for barley. Ten major clusters defined most of the population structure based on geographical origin, row type of the ear and caryopsis type – and were assigned to specific climate zones. The legacy core reference set Lrc648 established in this study will provide a long-lasting resource and a very valuable tool for the scientific community. Lrc648 is best suited for multi-environmental field testing to identify candidate genes underlying quantitative traits but also for allele mining approaches.

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“…Moreover, the regeneration process itself, performed largely via sexual reproduction, brings the danger of the original genetic spectra loss (Breese 1989). Lehmann and Mansfeld (1957) pointed out that all accessions should be efficiently described and suggested the comparison with reference material to monitor the status of accessions after regeneration. Modern techniques of seed storage in air-tight containers, low temperature and humidity (-20°C, 3-7% humidity), affirm viability maintenance of over 100 years (Roberts and Ellis 1984).…”

Section: Introductionmentioning

confidence: 99%

Molecular evidence of genetic diversity changes in pea (Pisum sativum L.) germplasm after long-term maintenance

Cieslarová

Smýkal

Dočkalová

et al. 2010

Genet Resour Crop Evol

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Maintaining germplasm genetic integrity is a key objective of long-term ex situ conservation. Periodic regeneration, performed on limited plots with small number of individuals, increases the risk of genetic drift and genetic diversity changes. In this study, six accessions of white flowered, dry seed pea varieties (Pisum sativum L. subsp. sativum var. sativum): Bohatýr, Klatovský zelený, Hanák, Moravský hrotovický krajový, Raman and Viktoria-75 and four accessions of colour flowered, fodder pea (P. sativum subsp. sativum var. arvense (L.) Poiret: Arvika, Č eský banán, Moravská krajová and Niké, representing Czechoslovak varieties and landraces, bred over the last 40-80 years, were analyzed using ten microsatellite locus specific markers. Each accession was represented by 20 individual seeds of two temporally different samples, spanning the period of 20 or 40 years. Together with intra-accession variation (except of cv. Hanák), evidence of genetic changes, e.g. differences in allele frequencies as well as genetic composition of sample, was detected in six out of ten accessions (Arvika, Bohatýr, Č eský banán, Moravský hrotovický krajový, Moravská krajová and Raman). Evidence of genetic erosion was found in three accessions (Č eský banán, Moravský hrotovický krajový and Raman), while in another three (Arvika, Bohatýr and Moravská krajová) the level of diversity was found to have increased. Moreover in three samples of Bohatýr (2004) and Klatovský zelený (1963 and2004), low levels of heterozygosity was detected. These results demonstrate that in pea, a selfpollinating and highly homozygous plant, the danger of the loss of genetic integrity exists. These findings are significant for long-term ex situ germplasm management.

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Zur Technik der Sortimentserhaltung

Cited by 30 publications

References 0 publications

Duplication assessments in Nordic Avena sativa accessions at the Canadian national genebank

Duplication assessments in Nordic Avena sativa accessions at the Canadian national genebank

Genetic Diversity and Population Structure in a Legacy Collection of Spring Barley Landraces Adapted to a Wide Range of Climates

Molecular evidence of genetic diversity changes in pea (Pisum sativum L.) germplasm after long-term maintenance

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