FRUCTAN AND SUGARS IN 273 OAT ACCESSIONS

Oat (Avena sativa L.) reportedly accumulates less fructan during hardening 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 accessions grown under controlled conditions. Dicktoo barley (Hordeum vulgare L.) was included as a high degree of polymerization (DP) fructan check. After 3 wk of hardening, plant stems (1 cm above the crown) were ground and extracted with water. Carbohydrates were separated by high performance liquid chromatography (HPLC) and quantified by comparison of peak areas in known standards to that in unknowns. On a fresh weight basis more than half the accessions had total fructan (DP > 2) levels not significantly (P < 0.05) different from Dicktoo barley, however, all but one accession had less (P < 0.05) high DP fructan (DP > 4) than Dicktoo. Based on the percentages of five carbohydrates, the accessions were grouped into eight clusters. One of the five species analyzed was alone in a cluster, the remaining species were spread across several clusters. Genetic variability for fructan concentration is apparently high enough in the accessions analyzed in this study to permit more detailed physiological studies with fewer accessions with a wide range of fructan content.