C.L. QUARÍN¹, J.F.M. VALLS² and M.H. URBANI¹

¹Facultad de Ciencias Agrarias, UNNE, Instituto de Botánica del Nordeste, Corrientes, Argentina
²Centro Nacional de Pesquisa de Recursos Genéticos e Biotecnologia, Empresa Brasileira de Pesquisa Agropecuária, Brasilia, Brazil

Abstract

Paspalum atratum is a wild species native to central-western Brazil, with a great potential for forage production, good palatability and good seed production. Research is now aiming to domesticate the species and bring it into cultivation. The objective of this work was to determine chromosome number, meiotic chromosome behaviour, and method of reproduction of P. atratum. This information is essential for any program dealing with plant breeding and plant improvement. Our results indicate that the accession BRA 009610 is tetraploid (2n = 4x = 40) with a mean chromosome association of 0.06 I, 19.03 II, and 0.47 IV per pollen mother cell at first meiotic metaphase. Embryological and experimental data demonstrate that this accession is apomictic with aposporous embryo sac formation followed by parthenogenesis. Thus, plant selection or crosses will be fruitless in breeding programs unless a sexual or partially sexual form of the species (or related compatible species) can be identified. Because this accession is apomictic, it can be grown in proximity to other accessions for seed production without risk of contamination through pollen.