Relationship between Orchardgrass Seed Production in Indiana and Oregon
- S. D. Stratton and
- H. W. Ohm
Orchardgrass, Dactylis glomerata L., is an important forage species in the eastern USA, but nearly all commercial seed is produced in Oregon. The objectives of this study were to: (i) determine relationships among Orchardgrass seed yield traits, and (ii) examine the feasibility of selection in Indiana for improved seed yield in Oregon. Twenty-four Orchardgrass parents and their polycross progenies were randomly selected from a reference population, and established as spaced plants at Battle Ground and Buck Creek, IN, and Salem, OR for evaluation of seed yield and associated traits. Progenies were also established as seeded rows at all locations for seed yield evaluation. In the space-planted study, genotypic variation was found for panicle number, seed yield, and yield per panicle in Indiana, and Oregon. Phenotypic correlations indicated that panicle number (r = 0.46–0.77) and yield per panicle (r = 0.17–0.66) were associated with seed yield. Genotypic ✕ location interactions between Indiana and Oregon were significant (P < 0.05) for panicle number, seed yield, and yield per panicle. Phenotypic and genetic correlations were low for seed yield per plant, (r = –0.19 to 0.55), panicle number per plant (r = 0.06–0.54), and seed yield per panicle (r = −0.08 to 0.68) in comparisons between Indiana and Oregon. Heritability values on a plot basis (h2 = −1.19 to 0.37) and parent-progeny correlations (r = −0.32 to 0.12) for seed yield were low at all locations. Genotypic variation for seed yield was detected only in Oregon among seeded progeny rows. Phenotypic (r = −0.35 and 0.51) and genetic (near zero) correlations for seed yield between Indiana and Oregon seeded progeny rows were low. Low phenotypic and genetic correlations for seed yield between Indiana and Oregon, and significant genotype ✕ location interactions indicated that it would be difficult to improve Oregon seed yield through selection in Indiana within this population. The low heritability values indicated that it is necessary to practice selection of families rather than individual plants to improve seed yield.
Copyright © 1989.