FRUCTAN AND SUGARS IN 273 OAT ACCESSIONS

Oat (Avena sativa L.) reportedly accumulates less fructan during harde ning than other winter cereals. Little is known about the variability for fructan concentration after hardening in the genus Avena, however. To investigate genetic variability, fructan was measured in 273 oat a ccessions grown under controlled conditions. Dicktoo barley (Hordeum v ulgare L.) was included as a high degree of polymerization (DP) fructa n check. After 3 wk of hardening, plant stems (1 cm above the crown) w ere ground and extracted with water. Carbohydrates were separated by h igh performance liquid chromatography (HPLC) and quantified by compari son of peak areas in known standards to that in unknowns. On a fresh w eight basis more than half the accessions had total fructan (DP > 2) l evels not significantly (P < 0.05) different from Dicktoo barley, howe ver, all but one accession had less (P < 0.05) high DP fructan (DP > 4 ) than Dicktoo. Based on the percentages of five carbohydrates, the ac cessions were grouped into eight clusters. One of the five species ana lyzed was alone in a cluster, the remaining species were spread across several clusters. Genetic variability for fructan concentration is ap parently high enough in the accessions analyzed in this study to permi t more detailed physiological studies with fewer accessions with a wid e range of fructan content.