Recurrent Selection for Test Weight and Grain Yield of Oat

Abstract

Continued advances in oat (Avena sativa L.) breeding rely in part on the improvement of test weight and grain yield while maintaining genetic variability. The objective of this study was to determine the efficacy of three cycles of recurrent selection for high test weight (HT population) or Smith‐Hazel index of test weight and grain yield (HTG population) in oat. The recurrent selection procedure consisted of intermating selected S0:1 lines, growing the S0 seeds to produce S0:1 lines, and field evaluating the S0:1 lines. Each cycle took 1 yr to complete and about 300 lines were evaluated in each population of each cycle. Twenty S0:1 lines were selected from each population to initiate the next cycle. Response to selection in a population was evaluated by testing 95 S0:1 lines randomly chosen from among Cycles 0, 1, and 2, the complete Cycle 3 population, parents from all cycles, and a set of check cultivars. There were significant (P < 0.05) increases in mean test weight of 17.8 ± 3.5 kg m−3 and 6.9 ± 1.5 kg m−3 per cycle in the HT and HTG populations, respectively. For grain yield, there was a significant decrease of 0.11 ± 0.03 Mg ha−1 per cycle in HT populations, and an increase of 0.12 ± 0.07 Mg ha−1 per cycle in HTG populations. Broad‐sense heritabilities and genotypic variances remained high in all cycles of each population. The results of this study show that recurrent selection in oat is an effective breeding procedure for improving test weight and grain yield without significant reductions in genetic variability.