Submitted to: Arkansas Agricultural Experiment Station Research Series
Publication Type: Experiment Station
Publication Acceptance Date: March 1, 2005
Publication Date: August 10, 2005
Citation: Yan, W., Rutger, J.N., Bockelman, H.E., Tai, T. 2005. Agronomic evaluation and seed stock establishment of the USDA rice core collection. In: Norman, R.J., Meullenet, J.-F., Moldenhauer, K.A.K., editors. B.R. Wells Rice Research Studies 2004, Arkansas Agricultural Experiment Station Research Series 529. p. 63-68. Available: http://www.uark.edu/depts/agripub/Publications/researchseries/ Technical Abstract: A total of 1,687 out of 1,801 accessions in the USDA rice core collection were planted in 2002 for agronomic evaluation and seed stock establishment. The remaining 114 accessions were undergoing an additional cycle of initial seed increases and were not included in these evaluations. Seed amounts ranging from 11 to 1633 g were harvested from 1,645 accessions, in which days from emergence to 50% heading varied from 42 to 180 days and averaged 97 +/- 19. Plant height ranged from 61 to 212 cm and averaged 126 +/- 25 cm. Twelve hundred seventeen or 75% of accessions had no lodging with ratings of 2 or less, and 187 or 11% lodged badly with ratings of 7 or more. The remaining 241 accessions were rated between 2 and 7 for lodging. Plant types included 41% erect, 35% intermediate, 21% open, 3% spreading, and zero procumbent. Panicle type of the core collection was 1% compact, 97% intermediate and 2% open. The core had 81% awnless, 5% short and part awns with a few short and full awns, 5% long and part awns, and 9% long and full awns. Late heading plants tended to be taller (r=0.22). Tall plants lodged more (r=0.40), and had less awning (r=-0.14). Open plant types had more lodging (r=0.13), and yielded more (r=0.16). Plants with open panicles were taller (r=0.15), and more awned (r=0.85). All these correlations were significant at 0.01 probability level.