Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/20/2007
Publication Date: 1/15/2008
Citation: Casler, M.D., Undersander, D.J., Jokela, W.E. 2008. Divergent Selection for Phosphorus Concentration in Orchardgrass and Reed Canarygrass. Crop Science.48:119-126. Interpretive Summary: Phosphorus is a vital nonrenewable natural resource that is essential for plant and animal growth. Grass swards and/or buffer strips can be utilized to reduce phosphorus (P) losses that occur by soil erosion, surface runoff, or leaching. Our goal was to develop grasses with higher phosphorus concentration and uptake for use in "mining" phosphorus from high-P soils. We were successful in increasing P content in reed canarygrass, but not in orchardgrass. Our research identified some ways in which we could improve our breeding and selection techniques. These results will be useful to agronomists and plant breeders who have an interest in plant mineral nutrition.
Technical Abstract: Phosphorus is a vital nonrenewable natural resource that is essential for plant and animal growth. Grass swards and/or buffer strips can be utilized to reduce P losses that occur by soil erosion, surface runoff, or leaching. The objective of this study was to conduct one cycle of divergent selection for P concentration in orchardgrass (Dactylis glomerata L.) and reed canarygrass (Phalaris arundinacea L.) and to evaluate the effects of selection on P concentration, forage yield, and P uptake. Divergent selections and original populations were evaluated in sward plots, harvested three times per year for 2 years at three locations. Divergent selection for P concentration in orchardgrass was ineffective, as selection responses followed a pattern expected from random genetic drift. Selection responses in reed canarygrass indicated that P concentration has a moderate to high narrow-sense heritability; that genetic gains are highly repeatable across harvests, locations, and years; and that there is a negative genetic correlation between P concentration and sward-plot forage yield. Future selection efforts must be based on genotypic selection methods, in which half-sib families are evaluated for forage yield, P concentration, and P uptake in sward plots.