FIELD-EVALUATION OF SEEDLING ROOT LENGTH SELECTION IN OATS

Selections for long and short root length were made on 10-day-old oat, seedlings from 2 F2 populations grown in distilled water or in a modified half-strength Hoagland''s solution. F2 derived F3 and F4 progeny were grown in the field in a nonstress environment with a shallow (10-30 cm) loamy sand or sandy loam A horizon and in a stress environment with a deep (75-90 cm) loamy sand A horizon. Seedling root measurements were made on F4 and F5 plants. Root length differences were observed 2 and 3 generations after selection following growth in a modified half-strength Hoagland''s solution but differences between long and short root length selections were not consistently maintained for the selections made after growth in distilled water. Trends toward greater grain yield, seed number and plant height were observed for the long root length selection, especially in the nonstress environment. The technique was not successful in identifying plants with superior performance in a deep sandy soil.