Catálogo de publicaciones - tesis
Título de Acceso Abierto
Genética y localización del locus de la apomixis en especies del grupo Plicatula de Paspalum L. reveladas por técnicas moleculares
Patricia Mabel Aguilera Francisco Espinoza Juan Pablo Amelio Ortiz
acceptedVersion.
Resumen/Descripción – provisto por el repositorio digital
Apomixis is a mode of asexual reproduction through seeds that originate progeny that is genetically identical to the mother plant. It is significant in the subfamily Panicoideae and genera Paspalum and its importance is given by the evolutionary connotations and its implications in breeding plant. Paspalum (Poaceae) is a genus comprising between 330 and 400 natural species of tropical, subtropical and temperate regions, mainly from North America and South America. Plicatula group of Paspalum comprises many promising species as forage resources and several of them are typical on natural fields of northeastern Argentina. Most apomictic species are tetraploid and usually possess sexual diploid co-specific counterparts. Sexual tetraploid plants have not been found in nature so far. The objectives of this research were: to generate a segregating population for the reproductive mode by crossing Paspalum plicatulum 4PT (completely sexual, experimentally induced) and P. guenoarum GR19 (natural apomictic) at tetraploid level, to construct genetic linkage maps of both species, to localize the region responsible for apomixis on the male map, to investigate the mode of inheritance (tetrasomic or disomic) of both parental genotypes. An interspecific hybrid population of 211 F1 plants, segregating for reproductive mode, was generated. Classification of 206 hybrids showed that 127 of them were sexual and 79 apomictic. The progeny showed morphological characteristics intermediate compared to their parents but resembling more the male plant. Inheritance of apomixis in Plicatula species showed a segregation distortion of 1.6:1, favoring to sexual individuals. This proposed apomixis segregation model in Plicatula is a novelty for interspecific hybrids of Paspalum. P. guenoarum and P. plicatulum are autotetraploids and both species show tetrasomic inheritance, according to the DDA markers of both genotypes that fixed to the 5:1 ratio. Moreover, some regions of both parental genomes showed disomic inheritance (markers 3:1 and bivalent chromosome associations). Both species share the same basic genomic complement. Seventeen AFLP primer combinations were assayed in 89 F1 individuals (55 sexual and 34 apomictic). The female genetic linkage frame map consisted of 89 markers [39 maternal (1:1) and 50 biparental (3:1)] assigned to 11 cosegregation groups, covering a distance of 819 cM. The genetic male linkage frame map was formed by 127 markers [76 paternal (1:1 and 1:1.6) and 51 biparental (3:1)], that were distributed in 23 cosegregation groups, spanning 1393 cM. The linkage group carrying apomixis (apo group, M10) was identified on the male map. Seven markers mapped onto the M10 linkage group: the character apomixis, 5 paternal markers and a biparental marker. Paternal markers that mapped onto M10 and apomixis showed segregation distortion, thus confirming the distorted transmission of the character and its associated genomic region. Unlike the data for other aposporic Paspalum species and other grasses, markers completely linked to apomixis have not been detected in P. guenoarum. Two paternal markers mapped to 4 and 7 cM from apomixis locus. Results presented in this work indicated that Plicatula species may be different cases from those previously described in the genus. Probably, P. guenoarum represents a new model for studying apomixis in Paspalum.Palabras clave – provistas por el repositorio digital
Genética; Técnicas moleculares
Disponibilidad
| Institución detectada | Año de publicación | Navegá | Descargá | Solicitá |
|---|---|---|---|---|
| No requiere | 2013 | Repositorio Institucional de la Universidad Nacional del Nordeste (SNRD) |
|
Información
Tipo de recurso:
tesis
Idiomas de la publicación
- español castellano
País de edición
Argentina
Fecha de publicación
2013
Información sobre licencias CC
