Registration of Arkansas Hull‐Less Oat Composite Germplasm

Arkansas Hull-Less Oat, a composite germplasm of nakedseeded oat (Avena nuda L.) (Reg. no. GP-56, PI 610259), was released in 1999 by the Arkansas Agricultural Experiment Station. The purpose of the release was to provide a gene pool for selection of naked-seeded oat lines with good winter hardiness adapted to the winter oat region in the southern USA. The original population was formed by compositing F2 seed of 37 crosses made by the oat breeding program at the University of Arkansas in 1988. In 10 of these crosses, 'Pennuda' (1) and the breeding line 'Coker 84-27' were used as sources for the naked-seeded trait. Pennuda and AR FOB 29 were used as sources of lodging resistance. The Arkansas breeding lines had relatively high levels of winter hardiness and straw strength. AR FOB 30 and AR O2848 had high test weight and grain yield. The Ft plants were grown at Aberdeen, ID, during the summer of 1989. The F2 generation was grown in thinly planted single row plots, and the seed was bulk harvested to form the original composite. The F3-F8 generations were planted in plots and subjected to natural selection for desirable plant characteristics, such as winter hardiness and resistance to diseases present at Stuttgart, AR. After harvest of the F3-F7 generations, seed expressing the naked-seeded characteristic were selected by hand and advanced to the next generation. Because of the continued selection for hull-less type, it is assumed that only the progeny from crosses involving a naked-seeded parent remain in the population (Table 1). To maintain a high level of genetic diversity, no other selection criteria was used on the seed. The germplasm has good winter survival, grows vigorously, and appears to be well adapted to Arkansas conditions. The nonreplicated yield at Stuttgart in 1998 was 2412 kg ha~'. This is comparable to the mean of the adjacent 1997-1998 Oat Cultivar Performance Test (2) at Stuttgart (2917 kg ha"), considering that all of the entries in that test were hulled (2917 kg ha' 30% hulls = 2042 kg ha'). In a replicated breeding trial in 1999, it yielded slightly more than 'Ozark'(3) (2917 kg ha vs. 2412 kg ha') not adjusting for the difference in hulls. There are several genotypes in the composite that express good straw strength. The maturity of the germplasm ranges from early to late. Plant height ranges from 52 to 125 cm. Groats vary in size, the majority being moderately plump (1000-kernel wt. = 29.0 g), with a range of high to low density of hairs (trichomes). Seed of the naked oat germplasm is higher in protein (15.5%) compared with the oat cultivars 'Bob' (4) (11.9%) and Ozark (oats—11.1%, groats—13.6%). It is also higher in fat, calories, and fiber content compared with Ozark groats. This composite should provide a germplasm source that is higher in protein and energy than current Arkansas oat cultivars. The generation of the germplasm at the time of seed release is F9 with the population approximately 70% naked seeded. Small quantities of seed are available upon written request to the corresponding author. It is encouraged that appropriate recognition of the source be given when the germplasm is used in development of new cultivars, parental lines, germplasm, or genetic stocks.