Effect of population combinations in the reproductive success and germination of seeds of Bromus auleticus (Poaceae)

GUTIERREZ HUGO; PENSIERO J.F.; ZABALA J.M.

GRASS AND FORAGE SCIENCE (PRINT)

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2015 vol. 70 p. 176 - 184

0142-5242

Bromus auleticus is known for its qualities as forage but domestication has limitations related to seed production technology and farm-scale seed propagation. The effect of different combinations of population in the reproductive success and seed germination of a relict population of central Argentina of B. auleticus was studied. The tests used a population of Santa Fe (SF) as the recipient of pollen and three populations as donors (LP: La Pampa, ER: Entre Ríos and BA: Buenos Aires). Reproductive success (proportion of flowers that become fruits) in seeds from 5-pollination treatments: a) control (SFxSF), b) LP, c) ER, d) BA  and e) mixture of donor was determined. Three temperature conditions were evaluated for germination: a) 15 ºC, b) 28 ºC and c) alternating 15-28 ºC (12 hours each) temperatures. There were significant differences in reproductive success depending on the source of pollen. Seeds obtained from new genotypic combinations did not increase their weight in relation to the pollen donor, and germination behaviour was more affected by extrinsic factors (temperature) than by their genetic origin. This work contributes added knowledge to previous studies regarding the effect of population size in self-incompatible species, and also provides an innovative approach as to the study of factors affecting the production of seeds of B. auleticus. The results confirm the hypothesis that a mixture of genotypes from a diverse origin increases the quantity of flowers that become fruits, which is of great importance to improved seed production in this forage species.