Beschreibung:
<jats:sec><jats:label /><jats:p><jats:italic>Low phytic acid</jats:italic> (<jats:italic>lpa</jats:italic>) crops have reductions in the amount of seed phytic acid (<jats:italic>myo</jats:italic>‐inositol hexa<jats:italic>kis</jats:italic>phosphate, InsP<jats:sub>6</jats:sub>) and increases in inorganic phosphorus (Pi) with little change to the amount of total seed P. In this study, four barley <jats:italic>lpa</jats:italic> genotypes (<jats:italic>lpa</jats:italic>1–2, <jats:italic>lpa</jats:italic>2–1, <jats:italic>lpa</jats:italic>3–1, and M955), backcross wild‐type (<jats:italic>wt</jats:italic>) sib‐selections, and original parental line ‘Harrington’ were grown in the field over 2 yr. Developing seed was harvested once a week for 3 wk and then again at physiological maturity, and the seeds assayed for levels of total P, Pi, and phytic acid P. Total phosphorus concentration showed no consistent differences between the <jats:italic>lpa</jats:italic> genotypes and Harrington. Inorganic P declined during development in the <jats:italic>wt</jats:italic> genotypes; however in <jats:italic>lpa</jats:italic> genotypes, inorganic P declined during the first few weeks of development, and then increased from 24 d to maturity. Phytic acid concentration increased steadily during development for the <jats:italic>wt</jats:italic> lines and barley <jats:italic>lpa</jats:italic>1–1 and <jats:italic>lpa</jats:italic>2–1, although the increase was much slower in the <jats:italic>lpa</jats:italic> lines. The <jats:italic>lpa</jats:italic>3–1 and M955 had very little InsP<jats:sub>6</jats:sub> accumulation until later in development, with little to no increase in the amount of phytic acid in mature seed of M955 compared to the developing seeds of <jats:italic>lpa</jats:italic>3–1. This information is useful in understanding timing of phosphorus accumulation in seeds, as well as the nature of the <jats:italic>low phytic acid</jats:italic> mutation in seed development.</jats:p></jats:sec>