Genetics, cytogenetics, and reproductive biology of Brachiaria
Two essentials for breeding new cultivars of Brachiaria are germplasm diversity and information on basic biological aspects of major species. This paper reviews current knowledge on the cytological behavior, mode of reproduction and its inheritance, and crossing compatibility of different species. T...
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| Format: | Book Chapter |
| Language: | Inglés |
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International Center for Tropical Agriculture
1996
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| Subjects: | |
| Online Access: | https://hdl.handle.net/10568/82032 |
| _version_ | 1855515027698614272 |
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| author | Valle, Cacilda Borges do Savidan, Yves H. |
| author_browse | Savidan, Yves H. Valle, Cacilda Borges do |
| author_facet | Valle, Cacilda Borges do Savidan, Yves H. |
| author_sort | Valle, Cacilda Borges do |
| collection | Repository of Agricultural Research Outputs (CGSpace) |
| description | Two essentials for breeding new cultivars of Brachiaria are germplasm diversity and information on basic biological aspects of major species. This paper reviews current knowledge on the cytological behavior, mode of reproduction and its inheritance, and crossing compatibility of different species. The two of major agronomic importance-B. decumbens and R brizantha-are tetraploid (2n = 4x = 36) and apomictic, that is, the embryo is produced without fusion of male and female gametes. Apomixis, although not common, is found throughout the plant kingdom and is often associated with polyploidy. Hence, it is frequently accompanied by meiotic anomalies leading to reduced pollen fertility. Sexuality has been found at the diploid level in these species and in R ruziziensis, and is generally associated with regular chromosome pairing and division. As a breeding tool, apomixis offers several advantages, because it associates fixation of hybrid vigor with seed propagation. Apomictic hybrids breed true, and superior genotypes can be rapidly increased by seed. The discovery of completely sexual plants in cross-compatible species of Brachiaria and the development of practical clearing techniques for the observation of ovules prompted studies of inheritance of apomixis. Results suggest a simple, monogenic control of mode of reproduction, with apomixis dominant over sexuality. These investigations open up promising new possibilities for manipulating apomixis in breeding programs. |
| format | Book Chapter |
| id | CGSpace82032 |
| institution | CGIAR Consortium |
| language | Inglés |
| publishDate | 1996 |
| publishDateRange | 1996 |
| publishDateSort | 1996 |
| publisher | International Center for Tropical Agriculture |
| publisherStr | International Center for Tropical Agriculture |
| record_format | dspace |
| spelling | CGSpace820322025-11-05T16:53:58Z Genetics, cytogenetics, and reproductive biology of Brachiaria Valle, Cacilda Borges do Savidan, Yves H. brachiaria genetics reproduction cytogenetics chromosomes plant developmental stages apomixis genética reproducción citogenética cromosomas etapas de desarrollo de la planta Two essentials for breeding new cultivars of Brachiaria are germplasm diversity and information on basic biological aspects of major species. This paper reviews current knowledge on the cytological behavior, mode of reproduction and its inheritance, and crossing compatibility of different species. The two of major agronomic importance-B. decumbens and R brizantha-are tetraploid (2n = 4x = 36) and apomictic, that is, the embryo is produced without fusion of male and female gametes. Apomixis, although not common, is found throughout the plant kingdom and is often associated with polyploidy. Hence, it is frequently accompanied by meiotic anomalies leading to reduced pollen fertility. Sexuality has been found at the diploid level in these species and in R ruziziensis, and is generally associated with regular chromosome pairing and division. As a breeding tool, apomixis offers several advantages, because it associates fixation of hybrid vigor with seed propagation. Apomictic hybrids breed true, and superior genotypes can be rapidly increased by seed. The discovery of completely sexual plants in cross-compatible species of Brachiaria and the development of practical clearing techniques for the observation of ovules prompted studies of inheritance of apomixis. Results suggest a simple, monogenic control of mode of reproduction, with apomixis dominant over sexuality. These investigations open up promising new possibilities for manipulating apomixis in breeding programs. 1996 2017-06-20T09:00:36Z 2017-06-20T09:00:36Z Book Chapter https://hdl.handle.net/10568/82032 en Open Access application/pdf International Center for Tropical Agriculture Empresa Brasileira de Pesquisa Agropecuária Centro Nacional de Pesquisa de Gado de Corte (CNPGC) Valle, Cacilda Borges do; Savidan, Yves H.. 1996. Genetics, cytogenetics, and reproductive biology of Brachiaria . In: Miles, John W; Maass, Brigitte L; Valle, Cacilda Borges do; Kumble, Vrinda (eds.). Brachiaria: Biology, agronomy, and improvement . Centro Internacional de Agricultura Tropical (CIAT); Campo Grande, BR : Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA), Centro Nacional de Pesquisa de Gado de Corte (CNPGC), Cali, CO. p. 147-163. (CIAT publication no. 259) |
| spellingShingle | brachiaria genetics reproduction cytogenetics chromosomes plant developmental stages apomixis genética reproducción citogenética cromosomas etapas de desarrollo de la planta Valle, Cacilda Borges do Savidan, Yves H. Genetics, cytogenetics, and reproductive biology of Brachiaria |
| title | Genetics, cytogenetics, and reproductive biology of Brachiaria |
| title_full | Genetics, cytogenetics, and reproductive biology of Brachiaria |
| title_fullStr | Genetics, cytogenetics, and reproductive biology of Brachiaria |
| title_full_unstemmed | Genetics, cytogenetics, and reproductive biology of Brachiaria |
| title_short | Genetics, cytogenetics, and reproductive biology of Brachiaria |
| title_sort | genetics cytogenetics and reproductive biology of brachiaria |
| topic | brachiaria genetics reproduction cytogenetics chromosomes plant developmental stages apomixis genética reproducción citogenética cromosomas etapas de desarrollo de la planta |
| url | https://hdl.handle.net/10568/82032 |
| work_keys_str_mv | AT vallecacildaborgesdo geneticscytogeneticsandreproductivebiologyofbrachiaria AT savidanyvesh geneticscytogeneticsandreproductivebiologyofbrachiaria |