Interspecific hybrids between Paspalum plicatulum and P. oteroi: a key tool for forage breeding
AUTOR(ES)
Novo, Patricia Elda, Valls, José Francisco Montenegro, Galdeano, Florencia, Honfi, Ana Isabel, Espinoza, Francisco, Quarin, Camilo Luis
FONTE
Sci. agric. (Piracicaba, Braz.)
DATA DE PUBLICAÇÃO
2016-08
RESUMO
ABSTRACT Grama-tio-pedro (Paspalum oteroi Swallen) is a rare stoloniferous grass of the Plicatula group of Paspalum, well adapted to continuous grazing in areas subject to seasonal flooding in the Pantanal region, in central western Brazil. The species is a facultative apomictic (asexual reproduction by seed) tetraploid, sporadically cultivated on Pantanal farms, propagated either by cuttings or seed. Due to its potential for extensive cultivation and forage quality, Grama-tio-pedro appears as a candidate for genetic improvement within the Plicatula group through plant breeding. We used a colchicine-induced sexual autotetraploid genotype of P. plicatulum Michx. to obtain interspecific hybrids using the apomictic species, P. oteroi, as pollen donor. The very similar meiotic chromosome behavior observed in both parents, with main quadrivalent and bivalent associations, suggested that P. oteroi is a natural autotetraploid. The hybrids showed less irregular meiotic behavior with fewer quadrivalents and more bivalents than either parent. Fertility among interspecific hybrids varied from complete sterility in some of them to seed productions in others that were approximately twice as much as for either parent. The great variability of seed set performance may well be a drastic genetic consequence of joining two homologous chromosome sets of P. plicatulum together with two homologous sets of P. oteroi that, in turn, have some homeology between them. Most hybrids reproduce by sexual means, thus, they could be used as female parents in backcrosses and in crosses with other species of the Plicatula group for interspecific gene transferring in breeding programs.
Documentos Relacionados
- Forage potential of native ecotypes of Paspalum notatum and P. guenoarum
- Genetic assessment of seed yield-related traits in superior hybrids of Paspalum plicatulum × Paspalum guenoarum
- Genetic parameters and predicted gains with selection of interspecific hybrids of Paspalum for seed production
- Aspectos morfofisiológicos e bromatológicos de Paspalum plicatulum
- Genetic variability of the components of seed yield in interspecific hybrids of Paspalum