Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/30/1999
Publication Date: N/A
Interpretive Summary: Mineral balance in animal feed is difficult to obtain when feeding alfalfa to dairy cows. Genetic manipulation of the alfalfa plant towards specific needs of the animal would simplify the maintenance of mineral balance. This study assayed for differences in mineral uptake among 4 germplasm pools representing the range of dormancy found in alfalfa. A field study was planted and data collected for 2 years. The more dormant germplasm pools, Flemish and Ladak, had the highest P and K content coupled with the lowest Ca. Data suggested that Ca was not correlated with P. This should prove beneficial, as selection for increased P levels in alfalfa (desirable for dairy cows) with subsequent drop in Ca levels is a desirable plant-breeding goal. Based upon the results of this study, it was concluded that Flemish-based germplasm was the best source of material to work with to accomplish this plant breeding goal.
Technical Abstract: Rapid expansion of dairy herds in the southwestern United States of America has increased the need for high-quality alfalfa forage in the region. Enhancing mineral balance in alfalfa could benefit both plant and animal production. The objective of this study was to survey four ancestral alfalfa germplasms for variability in shoot mineral concentration and for phenotypic associations among mineral concentration. African, Chilean, Flemish, and Ladak, and the check cultivar Moapa 69, were evaluated in a two year irrigated fields steady near Las Cruces, NM. Ten plants per plot were evaluated for P, Ca, S, Mg, K, B, Cu, Fe, and Mn concentration using an inductively-coupled plasma spectrometer. The more dormant germplasms, Flemish and Ladak, generally had the highest P and K concentrations and lowest calcium concentration in both years. Flemish germplasms also possessed relatively high concentrations of S, Na, Fe, and Mn. A greater proportion of significant phenotypic correlations between minerals was observed in this study than in previous reports. These results suggest that Flemish based parental populations should provide useful genetic material for enhancing mineral concentration in alfalfa forage.