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Registro Completo |
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Biblioteca(s): |
Embrapa Cerrados. |
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Data corrente: |
25/08/2010 |
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Data da última atualização: |
26/04/2019 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Autoria: |
PESSOA FILHO, M. A. C. de P.; RANGEL, P. H. N.; FERREIRA, M. E. |
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Afiliação: |
MARCO AURELIO CALDAS DE PINHO PESSO, CPAC; PAULO HIDEO NAKANO RANGEL, CNPAF; MARCIO ELIAS FERREIRA, CENARGEN. |
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Título: |
Extracting samples of high diversity from thematic collections of large gene banks using a genetic-distance based approach. |
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Ano de publicação: |
2010 |
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Fonte/Imprenta: |
BMC Plant Biology, v. 10, n. 127, 2010. |
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Idioma: |
Inglês |
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Conteúdo: |
Background
Breeding programs are usually reluctant to evaluate and use germplasm accessions other than the elite materials belonging to their advanced populations. The concept of core collections has been proposed to facilitate the access of potential users to samples of small sizes, representative of the genetic variability contained within the gene pool of a specific crop. The eventual large size of a core collection perpetuates the problem it was originally proposed to solve. The present study suggests that, in addition to the classic core collection concept, thematic core collections should be also developed for a specific crop, composed of a limited number of accessions, with a manageable size.
Results
The thematic core collection obtained meets the minimum requirements for a core sample - maintenance of at least 80% of the allelic richness of the thematic collection, with, approximately, 15% of its size. The method was compared with other methodologies based on the M strategy, and also with a core collection generated by random sampling. Higher proportions of retained alleles (in a core collection of equal size) or similar proportions of retained alleles (in a core collection of smaller size) were detected in the two methods based on the M strategy compared to the proposed methodology. Core sub-collections constructed by different methods were compared regarding the increase or maintenance of phenotypic diversity. No change on phenotypic diversity was detected by measuring the trait "Weight of 100 Seeds", for the tested sampling methods. Effects on linkage disequilibrium between unlinked microsatellite loci, due to sampling, are discussed.
Conclusions
Building of a thematic core collection was here defined by prior selection of accessions which are diverse for the trait of interest, and then by pairwise genetic distances, estimated by DNA polymorphism analysis at molecular marker loci. The resulting thematic core collection potentially reflects the maximum allele richness with the smallest sample size from a larger thematic collection. As an example, we used the development of a thematic core collection for drought tolerance in rice. It is expected that such thematic collections increase the use of germplasm by breeding programs and facilitate the study of the traits under consideration. The definition of a core collection to study drought resistance is a valuable contribution towards the understanding of the genetic control and the physiological mechanisms involved in water use efficiency in plants. MenosBackground
Breeding programs are usually reluctant to evaluate and use germplasm accessions other than the elite materials belonging to their advanced populations. The concept of core collections has been proposed to facilitate the access of potential users to samples of small sizes, representative of the genetic variability contained within the gene pool of a specific crop. The eventual large size of a core collection perpetuates the problem it was originally proposed to solve. The present study suggests that, in addition to the classic core collection concept, thematic core collections should be also developed for a specific crop, composed of a limited number of accessions, with a manageable size.
Results
The thematic core collection obtained meets the minimum requirements for a core sample - maintenance of at least 80% of the allelic richness of the thematic collection, with, approximately, 15% of its size. The method was compared with other methodologies based on the M strategy, and also with a core collection generated by random sampling. Higher proportions of retained alleles (in a core collection of equal size) or similar proportions of retained alleles (in a core collection of smaller size) were detected in the two methods based on the M strategy compared to the proposed methodology. Core sub-collections constructed by different methods were compared regarding the increase or maintenance of phenotypic diversity. No change on phenotypic diversity was detected by me... Mostrar Tudo |
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Palavras-Chave: |
Melhoramento genético; Variabilidade genética. |
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Thesagro: |
Genética; Germoplasma; Polimorfismo genético. |
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Categoria do assunto: |
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Marc: |
LEADER 03194naa a2200205 a 4500
001 1860873
005 2019-04-26
008 2010 bl --- 0-- u #d
100 1 $aPESSOA FILHO, M. A. C. de P.
245 $aExtracting samples of high diversity from thematic collections of large gene banks using a genetic-distance based approach.
260 $c2010
520 $aBackground Breeding programs are usually reluctant to evaluate and use germplasm accessions other than the elite materials belonging to their advanced populations. The concept of core collections has been proposed to facilitate the access of potential users to samples of small sizes, representative of the genetic variability contained within the gene pool of a specific crop. The eventual large size of a core collection perpetuates the problem it was originally proposed to solve. The present study suggests that, in addition to the classic core collection concept, thematic core collections should be also developed for a specific crop, composed of a limited number of accessions, with a manageable size. Results The thematic core collection obtained meets the minimum requirements for a core sample - maintenance of at least 80% of the allelic richness of the thematic collection, with, approximately, 15% of its size. The method was compared with other methodologies based on the M strategy, and also with a core collection generated by random sampling. Higher proportions of retained alleles (in a core collection of equal size) or similar proportions of retained alleles (in a core collection of smaller size) were detected in the two methods based on the M strategy compared to the proposed methodology. Core sub-collections constructed by different methods were compared regarding the increase or maintenance of phenotypic diversity. No change on phenotypic diversity was detected by measuring the trait "Weight of 100 Seeds", for the tested sampling methods. Effects on linkage disequilibrium between unlinked microsatellite loci, due to sampling, are discussed. Conclusions Building of a thematic core collection was here defined by prior selection of accessions which are diverse for the trait of interest, and then by pairwise genetic distances, estimated by DNA polymorphism analysis at molecular marker loci. The resulting thematic core collection potentially reflects the maximum allele richness with the smallest sample size from a larger thematic collection. As an example, we used the development of a thematic core collection for drought tolerance in rice. It is expected that such thematic collections increase the use of germplasm by breeding programs and facilitate the study of the traits under consideration. The definition of a core collection to study drought resistance is a valuable contribution towards the understanding of the genetic control and the physiological mechanisms involved in water use efficiency in plants.
650 $aGenética
650 $aGermoplasma
650 $aPolimorfismo genético
653 $aMelhoramento genético
653 $aVariabilidade genética
700 1 $aRANGEL, P. H. N.
700 1 $aFERREIRA, M. E.
773 $tBMC Plant Biology$gv. 10, n. 127, 2010.
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| 73. |  | NEVES, P. C. F.; CASTRO, E. M. de; RANGEL, P. H. N. Arroz híbrido no Brasil. In: CONFERÊNCIA INTERNACIONAL DE ARROZ PARA A AMÉRICA LATINA E O CARIBE, 9.; REUNIÃO NACIONAL DE PESQUISA DE ARROZ, 5., 1994, Goiânia. Arroz na América Latina: perspectivas para o incremento da produção e do potencial produtivo: pôsteres e grupos de trabalho. Goiânia: Embrapa-CNPAF, 1996. v.2. p. 72. (Embrapa-CNPAF. Documentos, 62).| Tipo: Resumo em Anais de Congresso |
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