Correlated Response to Selection for Protein Yield in Oats After Three Cycles of Recurrent Selection

Abstract

Three oat {Avena sativa L.) populations (i.e., lines of descent), high grain yield (HG), high protein content (HP), and high protein yield per se (HGP), each developed by three cycles of Si recurrent selection, were evaluated for the effect of selection for groat-protein yield upon other agronomic traits. Selections making up the HG line of descent had high protein yield primarily due to high grain yield, and those selected for HP had high protein yield due to both high protein content and high grain yield. Selection in HGP was on the basis of protein yield per se. Selection caused increases in bundle weight, harvest index, vegetative growth rate, and seed number in all lines of descent. Heading date, plant height, and seed weight were unaffected, whereas groat percentage and test weight were decreased in HP and HGP. Heritabilities were high for heading date, plant height, test weight, and seed weight, moderate for harvest index and bundle weight, and low for groat percentage. Genetic variability generally declined from GO to G3 for all traits.Groat-protein yield and amount of protein per groat increased in all lines of descent. In HG, the increase in groat weight was due primarily to increases in the nonprotein fraction, with groat-protein content actually decreasing. In HGP, groat weight increased due to increases in protein and nonprotein fractions, and groat protein content remained constant. In HP, groat weight and amount of nonprotein per groat decreased, thus increasing groat-protein content.

Health benefits of oat (Avena sativa) and nutritional improvement through plant breeding interventions

“…Protein content has high heritability (Humphreys and Mather 1996) and is affected by both genetic and environmental factors, particularly application of nitrogen fertiliser (Doehlert et al 2001;May et al 2004;Fan et al 2009). Further, McFerson and Frey (1992) confirmed that all wild species are superior to cultivars for protein content but that protein content was negatively correlated with grain yield, which makes introgression very difficult. Lipid content is a polygenic trait with high heritability and partial dominance (Branson and Frey 1989;Schipper and Frey 1991); therefore, recurrent selection towards population improvement has been preferred (Peterson and Wood 1997;Frey and Holland 1999).…”

“…The endosperm of the groat contains the majority of the lipid (86–90%) (Banaś et al . 2007; Menon et al . 2016), although reduced levels were also reported (Brown et al .…”

Effects of S1-recurrent selection for protein yield on seven agronomic traits of oat

“…Intense se ection for one trait, however, may cause favorab e or unfavorab e associated changes in other, unse ected agronomic traits . Se ection for grain or protein yie d in oat, for examp e, often wi resu t in p ant popu ations that are ate and ta , both of which are undesirab e (Stuthman, 1988;McFerson & Frey, 1992) . McFerson & Frey (1990) initiated three S, recurrent se ection programs (or ines of descent) for protein yie d in oat .…”

“…Means of grain yie d and agronomic traits of five ines with highest grain yie d in each ine of descent . responses toward ater maturity and ta er p ants (McFerson & Frey, 1992;Stuthman, 1988) .…”

Selection for high [beta]-glucan content in oat grain

“…On the other hand, unfavorable responses were observed for grain yield, biomass, and test weight whose means were reduced following selection in IABG2. For these traits, it is likely that the frequency of favorable alleles was reduced and response to direct selection to reverse the unfavorable responses in these traits will be reduced (McFerson and Frey, 1992…”