|Frey, Kenneth - IOWA STATE UNIVERSITY|
Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 30, 2000
Publication Date: N/A
Interpretive Summary: Higher oil oats could be useful as a higher energy animal feed or even as an oil seed crop for human food oil. In a previous study, we reported that nine cycles of selection for higher oil content in oat resulted in dramatic increases in oil content. Lines with oil content of up to 18% were developed; these are by far the highest levels of oil content ever reported din oat. For high oil oat cultivars to be accepted by growers, however, their agronomic characteristics must meet minimum standards. We evaluated oat lines from each of the nine cycles of selection and from the original unselected population for agronomic performance in field trials. Important grain quality traits such as test weight and seed weight and agronomic traits such as biomass and straw yield decreased following selection. Selection for increased groat-oil content reduced the mean grain quality and agronomic performance of the population. This suggests that high oil oat cultivars can not be developed directly from these experimental lines. By measuring the genetic correlations between agronomic traits and oil content, however, we found that it should be possible to select for oats that have a favorable combination of high oil and good agronomic performance. Direct simultaneous selection for all important traits will be required to achieve this goal.
Technical Abstract: Increases in the groat-oil content of oat (Avena sativa L.)raise the energy value of oat grain. Nine cycles of recurrent phenotypic selection for high groat-oil content were conducted in a genetically broad-based oat population resulting in dramatic increases in the groat-oil content of the population. Our objectives in this experiment were to determine if selection for high groat-oil content affected means, genetic variances, heritabilities, or genotypic or phenotypic correlations of grain quality traits (test weight and seed weight) and agronomic traits (straw yield, biomass, harvest index, heading date, and height). We evaluated 100 random lines from the base (CO) population and each of the nine selection cycle populations in three environments. All traits except harvest index decreased over cycles of selection. There was no evidence for reduced genetic variance or heritability in C9 for any trait, but the genotypic and dphenotypic correlations between agronomic traits and oil content fluctuate over cycles. These results suggest that selection for increased groat-oil content has reduced the mean grain quality and agronomic performance of the population. Selection for improved grain quality and agronomic performance in high oil content populations is predicted to be successful, however, because of the significant genetic variation for these traits remaining in the population. Combined selection for increased groat-oil content and agronomic performance would be most efficient if it were based on a selection index that accounted for the significant genotypic and phenotypic.