Recurrent selection in oat for adaptation to diverse environments

In order to test if selection can improve a population's adaptation to dive rse environments simultaneously, three cycles of recurrent selection based on grain yield in Iowa, Idaho, and Norway were practiced in an oat (Avena s ativa L.) population developed from North American, Scandinavian, and wild species (A. sterilis L.) germplasm sources. Specific objectives were to det ermine if selection: increased mean yields across environments and within a ll environments; changed the genetic correlation of yields in different env ironments; and changed genetic variation for yield within the population. W e evaluated 100 to 210 randomly-chosen families from each cycle of selectio n at three Iowa locations, in Idaho, and in Norway for two years. Grain yie ld within each location and mean yields across locations increased signific antly over cycles of selection. Mean yields across locations expressed as a percent of the original population mean increased at a rate of 2.6% per ye ar. Several families from the third cycle population exhibited both high me an yields across locations and consistently high yields within all location s. Average genetic correlations of yield in different environments were hig her in the second cycle than in the original population. A trend of reduced genetic variation and heritability was observed in Iowa only. These result s suggest that we successfully improved mean population yield both within a nd across locations, and yield stability across environments, and in develo ping families with outstanding adaptation to diverse environments.