IFEVA   02662
INSTITUTO DE INVESTIGACIONES FISIOLOGICAS Y ECOLOGICAS VINCULADAS A LA AGRICULTURA
Unidad Ejecutora - UE
artículos
Título:
Latitudinal variation of genecological traits in native grasses of Patagonian rangelands.
Autor/es:
LEVA, P.; AGUIAR, M.R.; PREMOLI, A.C.
Revista:
AUSTRALIAN JOURNAL OF BOTANY
Editorial:
CSIRO PUBLISHING
Referencias:
Lugar: Collingwood; Año: 2013 vol. 61 p. 475 - 485
ISSN:
0067-1924
Resumen:
Geographical variation in genetically-based traits helps to elucidate the effect of distinct ecological and evolutionary processes on widespread plants. While abundant information exists on current genetic patterns of woody species in west humid Andes, such information is scarce for neighboring dry Patagonian steppe. We examined genecological traits of two native forage species vulnerable to overgrazing (Bromus pictus and Poa ligularis) in dry Occidental Phytogeographical District. We compared within-population genetic diversity and among-population (n=6) divergence by isozyme electrophoresis. Also we cultivated plants to compare their morphology (plant height, number of tillers by plant, and weight per tiller). Analysis showed that 8 and 13 loci were polymorphic out of 9 and 19 resolved loci in at least one population for Bromus and Poa, respectively. Poa showed greater genetic variability than Bromus, probably due to ecological and life history differences. In general, plant traits were negatively associated with latitude in both species. Genetic and quantitative results (FST/QST index) showed evidence of local adaptation in populations of the two species. Genetic divergence among populations was significant. We detected two different geographical groups divided at the same latitude (42-43° S) in both species, supporting the hypothesis of a past vicariance event. Sustainable management of these forage species to cope with land-use and climate change will be enriched by the inclusion of genetic knowledge.