ROOT SIZE AND DISTRIBUTION OF FIELD-GROWN WHEAT GENOTYPES

Extraction of held grown wheat (Triticum aestivum L.) roots is cumbers ome, tedious, and labor intensive, whereas the roots of wheat plants g rown in hydroponics are clean and easy to extract. To determine if whe at root growth in hydroponics is related to held root growth and grain yield under varying soil conditions, we grew six winter wheat genotyp es in three field environments. Genotypes were selected based on the s ize of their root systems when grown hydroponically: three had large r oot systems and three had small root systems. Subsurface root length d ensity (SRLD) was measured from soil cores in incremental depths betwe en 13 and 120 cm. Averaged across environments, the root fresh weight in hydroponic culture was correlated with SRLD (r = 0.93*). As a grou p, genotypes with larger root systems in hydroponic culture produced l arger SRLD values and higher grain yields than did those with smaller root systems, but for individual genotypes, the correlation between SR LD and grain yield was not significant. Results from this limited numb er of genotypes indicate that selection for seedlings with large root systems in hydroponic culture may select genotypes capable of producin g more roots in the field.