Genetic variation for macro- and micro-nutrient concentration in perennial ryegrass (Lolium perenne L.)

Abstract

A perennial ryegrass breeding pool showed significant genetic variation for concentrations in leaf of 8 of 16 macro- and micro-nutrients measured. Narrow sense heritabilities (h²) ranged from 0 (B, Zn) to 0·9 (Mn, Na). Families selected for high and low herbage P concentrations (h² = 0·4) showed consistent behaviour over a range of soil P treatments in a separate experiment. Families similarly selected for herbage K concentrations (h² = 0·15) did not show such consistent response in a later experiment. High soil K reduced herbage Mg concentrations, but family means for herbage Mg and herbage K concentrations were not correlated. The data show that selection for herbage content of Mg, Na, or P is likely to be successful, but that herbage K is not simply regulated. These results have implications for livestock Mg metabolism, for efficiency of P and K use in mixed legume-based pastures, and for P and K wastage from pastures.