Comparison of S1 with Open-Pollination Progenies in Selection for Yield in Crested Wheatgrass
- John D. Berdahl *a and
- Ian M. Rayb
Genetic gain from selection for high dry matter yield in most cross-pollinated forage grasses has been an elusive goal, in spite of sustained breeding efforts. This study was conducted to determine the value of one generation of self-pollinating (S1) before selection for yield in crested wheatgrass (Agropyron spp.). Dry matter yields were compared at two locations near Mandan, ND, for synthetic populations derived from selection among and within S1 or among and within open-pollination (OP) progenies from three source populations. Within each source population, the 20 parents used to produce S1 progenies were in common with the 20 maternal parents of the OP progenies. Soil was a Parshall fine sandy loam (coarse-loamy, mixed, superactive, frigid Pachic Haplustolls) at Location 1 and a Wilton silt loam (fine-silty, mixed, superactive, frigid Pachic Haplustolls) at Location 2. In space-plant tests, S1 family means for dry matter yield averaged 52% of OP family means, indicating high levels of inbreeding depression. In solid-seeded tests, yield differences between S1– and OP-derived synthetic populations were significant (P ≤ 0.05) for only one comparison. On the basis of three distinct source populations, we found that S1 and OP families were both effective when used as the selection unit to choose high yielding parents for synthetic populations. Additional resources required to produce and evaluate S1 families over OP families could not be justified in the crested wheatgrass source populations evaluated in this study.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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