Characterization and analysis of a collection of Avena sativa L. from Uruguay

摘要

Oat production in Uruguay has traditionally been based on the use of landraces. These contain important genetic variability that is of great value for breeding. This variability must be accompanied by characterization and agronomic evaluation data tobe of real use. The objective of this research was to characterize and analyze a 120-accession Avena sativa L. collection that is kept at IMA 'La Estanzuela' (Uruguay). The collection is represented by four groups of accessions: (a) old varieties from the region that had been conserved in NPGS/USDA; (b) modern breeding lines from the Quaker Oats Evaluation Network Collection; (c) selections for differential resistance to leaf rust from two traditional cultivars; (d) landraces collected from farmers' fields, A total of 20 traits (18 quantitative and 2 qualitative) were determined during the vegetative, reproductive and maturity stages, and analyzed by univariate and multivariate statistical methods. The traits that showed the greatest discrimination ability between groups were number of tillers, leaf width and grain yield. Significant morphological and physiological differences among the four groups were observed, particularly between the farmer varieties and modern lines. These two groups of accessions represent two different taxa of the species Avena sativa L. (byzantina and sativa types, respectively). These groups have also experienced differential evolutionary pressures: the former have been highly affected by natut al selection driven by farmers' practices, such as intensive grazing, whereas the latter are the result of conventional breeding programmes aimed at improving grain yield.