EVALUATION OF TRAITS RELATED TO SEED QUALITY IN ACROCERAS MACRUM (NILE GRASS)

FERRARI USANDIZAGA, SILVANA CONSUELO; ACUÑA, CARLOS ALBERTO; BRUGNOLI, ELSA ANDREA; GÁNDARA, LUIS; MAIDANA, CARLOS EMILIO; MAY PETROFF, NOELIA; BASUALDO, JUAN PABLO

Pergamino

Congreso; 9° Congreso internacional de semillas forrajeras y céspedes; 2017

Acroceras macrum is a warm-season perennial grass native to tropical and subtropical regions ofAfrica. Its value as forage is due to the C3 photosynthetic pathway, offering higher nutritive valuethan C4 grasses. A. macrum is well adapted to wet or flooded Alfisols and vertisols of thenortheastern region of Argentina (NEA), where its use allows higher and more intense productionin comparison to the natural grasslands. Its adoption on production systems is limited because theunavailability of commercial seed, although vegetative implantation through rhizomes and stolonscan be achieved with excellent persistence. The tetraploid (2n = 4x = 36) cytotype of A. macrumavailable in Argentina presents wide genetic variability. The species is sexual, and it is possible toachieve viable seed by crosses between different 4x genotypes, with averages between 0 and69%. Our objective was to study some features related to A. macrum seed quality. Sixteenfamilies (a total of 160 hybrids) obtained by crossing different 4x genotype were studied. Seedswere collected throughout the flowering period. Seed varied on size, maturation degree andpigmentation (brown) degree. The largest (2.8 mm) and heaviest seeds (2.6g / 1000 seeds) had agermination (G) of 60% and a germinative energy (GE) of 30%, these were predominantlypigmented seeds. The lightest (1.2g / 1000 seeds) and smallest seed (2.2mm) had a G of 1.4% andan EG of 0%. Seeds with inmature aspect had G and EG of 0%. Significant differences in weight,seed filling and number of inflorescences produced per plant at peak flowering (mean 500-100panicles) were found among families. Based on these results, we have initiated a breedingprogram based in selection against seed quality features.