Genetic Variation and Breeding Potential of Phytate and Inorganic Phosphorus in a Maize Population
2008
Lorenz, Aaron J. | Scott, M Paul | Lamkey, Kendall R.
Seed P is predominantly bound in the organic compound phytate, which makes the bioavailability of P low for monogastric animals fed maize (Zea mays L.)-based diets. Decreasing phytate and increasing inorganic P (Pᵢ, an available form of P) concentrations in maize grain would be desirable to help ameliorate environmental problems associated with high P in feces. Our objective was to investigate the potential of improving the P profile of maize grain through breeding and selection. Ninety S₁ families from the BS31 population were evaluated at two locations for phytate, Pᵢ, and other grain quality and agronomic traits. Phytate concentrations ranged from 1.98 to 2.46 g kg⁻¹, and the broad-sense heritability (H) was relatively low (0.60). Both genetic variance and H (0.84) were much greater for Pᵢ Few unfavorable genetic correlations were observed between either Pᵢ or phytate and other key economic traits. Also, selection differentials of multiple trait indices indicated that the P profile of maize grain and grain yield and moisture could be improved simultaneously. Many cycles of selection will be needed, however, to reach desirable phytate and Pᵢ concentrations, especially when selecting for multiple traits. Regardless, our results are encouraging given that the families evaluated were related S₁ families and the number of families was relatively small.
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