The objective was to combine a set of crossing and evaluation techniques into a regime that permits a breeder to conduct one cycle of recurrent selection for protein or grain yield of oats (Avena sativa L.) per year. Parental strains are crossed in the greenhouse during September to December, S0 plants are propagated in the greenhouse during December to March, S0.1 lines are evaluated in a replicated multilocation experiment in the field during April to July, and data summary and selection of parental lines for a new cycle occur during August. The schedule is repeated for each cycle. Over three cycles, the gain per cycle (and per year) was 4.7% for protein yield and 5.4% for grain yield. Techniques employed to permit completion of a cycle of recurrent selection in 1 year were: (i) approach method of crossing, (ii) evaluating S0.1 lines, (iii) hill plots for field evaluation, (iv) infrared analyzer for N determinations, and (v) computer data analyses and line selection.

An improvement in the groat (caryopsis) oil content of oat (Avena sativa L.) may lead to the development of oat as an oilseed crop. Three cycles of phenotypic recurrent selection for high groat oil content were conducted in an introgressed oat gene pool, constructed by combining high‐oil alleles from A. sativa with those of its wild progenitor, A. sterilis L Selection for groat oil content was applied to individual So plants, with recombination among progenies from the highest 10% to form an improved population. One year was required to complete each cycle of selection. Gain from selection was evaluated by field testing 100 random and 100 selected lines from each of the C0, C1, C2, and C3 populations. Selection increased groat oil content linearly at a rate of 9.26 g kg−1 per cycle, which resulted in a linear increase in oil yield of 21 kg ha−1 per cycle. The largest gain from selection for both traits occurred in the first selection cycle. Broad‐sense heritability and genotypic variance remained high and significant in all cycles, which suggests continuing gains in groat oil content from additional cycles of recurrent selection. Realized heritability for groat oil content was 0.68 ± 0.05. Of the 400 random lines evaluated, the top 10 lines for groat oil content were from the C3 population, the highest individual line having a groat oil content of 144.8 g kg−1. That some high oil oat lines were equivalent to check cultivars for all agronomic traits suggests selection for oil content had little effect on those traits.

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One hundred random oat (Avena sativa L .) lines from a base (C0) and each of three populations (C l, C2, and C3) improved for groat (caryopsis) oil content by phenotypic recurrent selection were evaluated for correlated changes in several unselected agronomic traits . In addition, the parents of the base population and four check varieties were evaluated for the same traits . Phenotypic recurrent selection for high groat-oil content resulted in no significant correlated response in mean expression of any trait . Mean grain yield, biomass, groat yield, and harvest index of the improved populations were equal or superior to the mean of the parents and, with the exception of harvest index, equivalent to the mean of the check varieties . Mean test weight and seed weight of all populations were lower than for parents or check varieties . Selection for high groat-oil content caused a decline in genotypic variance for test weight and groat fraction, but reductions in genotypic variance for heading date and plant height may have resulted from culling for good agronomic type . Broad-sense heritability remained moderate to high for all traits except groat fraction . Phenotypic and genotypic correlation coefficients revealed negative, though mostly nonsignificant, relationships between groat-oil content and several traits, which may reflect a purported bioenergetic limitation to increasing groat-oil content in oats . Oil yield, however, was positively correlated with grain and groat yield, groat fraction, biomass, and harvest index . Results suggest that development of high-oil oat cultivars with current levels of production traits via phenotypic recurrent selection is possible .