RELATIONSHIPS AMONG NORTH-AMERICAN OAT CULTIVARS BASED ON RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISMS

Knowledge of genetic variability within a crop species is essential to its improvement. The objectives of this study were to assess restrict ion fragment length polymorphism (RFLP) patterns for oat (Avena sativa L. and A. Byzantina K. Koch) cultivar characterization, to estimate g enetic relationships among oat cultivars based on RFLP patterns, and t o contrast these estimates with genetic relationships obtained from pe digree information. Eighty-three North American oat cultivars were sub jected to RFLP analyses using 48 oat and barley (Hordeum vulgare L.) c DNA clones selected to represent a large portion of the genome. The 46 polymorphic clones detected a total of 278 fragments, 205 (73.7%) of which were polymorphic. The number of fragments detected per polymorph ic clone varied from 2 to 11 with an average of 6.0 fragments per clon e (4.5 polymorphic fragments per clone). The average number of phenoty pes produced per clone was 8 (range of 1-25). All cultivars could be d istinguished with a minimum of 11 clones. The RFLP banding patterns we re used to generate a genetic distance matrix, which was used in both cluster and principal coordinate analyses. Both analyses clearly separ ated the spring and fall sown groups of cultivars, and further subgrou pings were consistent with available pedigree information. The RFLP-ba sed genetic distance matrix was compared with a matrix of coefficients of parentage for a subset of 55 cultivars. The Mantel statistic was h ighly significant (P < 0.01) but low (r = -0.32) indicating a moderate relationship between genetic distance derived from RFLP patterns and the pedigree-based coefficient-of-parentage. The RFLP patterns could b e used to predict genetic relationships between germplasm of unknown o r ambiguous pedigrees as well as for the fingerprinting of North Ameri can oat cultivars.