Genome size and numerical polymorphism for the B chromosome in races of maize (Zea mays ssp. mays, Poaceae)
Twenty-one native populations (1120 individuals) of maize from Northern Argentina were studied. These populations, which belong to 13 native races were cultivated at different altitudes (80-3620 m). Nineteen of the populations analyzed showed B chromosome (Bs) numerical, polymorphism. The frequency...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 1998 |
| País: | Argentina |
| Institución: | Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales |
| Repositorio: | Biblioteca Digital (UBA-FCEN) |
| Idioma: | inglés |
| OAI Identifier: | paperaa:paper_00029122_v85_n2_p168_Rosato |
| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_00029122_v85_n2_p168_Rosato |
| Access Level: | acceso abierto |
| Palabra clave: | B chromosome DNA content Genome size Maize Maize native races Poaceae Zea mays ssp. mays Zea mays |
| Sumario: | Twenty-one native populations (1120 individuals) of maize from Northern Argentina were studied. These populations, which belong to 13 native races were cultivated at different altitudes (80-3620 m). Nineteen of the populations analyzed showed B chromosome (Bs) numerical, polymorphism. The frequency of individuals with Bs varied from 0 to 94%. The number of Bs per plant varied from 0 to 8 Bs, with the predominant doses being 0, 1, 2, and 3. Those populations with varying number of Bs showed a positive and statistically significant correlation of mean number of Bs with altitude. The DNA content, in plants without Bs (A-DNA)(2n = 20), of 17 populations of the 21 studied was determined. A 36% variation (5.0-6.8 pg) in A-DNA content was found. A significant negative correlation between A-DNA content and altitude of cultivation and between A-DNA content and mean number of Bs was found. This indicates that there is a close interrelationship between the DNA content of A chromosomes and doses of Bs. These results suggest that there is a maximum limit to the mass of nuclear DNA so that Bs are tolerated as long as this maximum limit is not exceeded. |
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