ARS | Publication request: GROWTH, DEVELOPMENT, AND PHYSIOLOGICAL CHARACTERISTICS OF SELECTED RED RICE (ORYZA SATIVA) ACCESSIONS FROM ARKANSAS

Submitted to: Arkansas Agricultural Experiment Station Research Series
Publication Type: Experiment Station
Publication Acceptance Date: July 6, 2005
Publication Date: August 10, 2005
Citation: Gealy, D.R. 2005. Growth, development, and physiological characteristics of selected red rice (Oryza sativa) accessions from Arkansas. 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. 184-200. Available: http://www.uark.edu/depts/agripub/Publications/researchseries/

Technical Abstract: Seed of 13 awnless strawhull, 5 awned strawhull, and 8 awned blackhull red rice accessions were obtained from Arkansas and other southern rice producing states and planted in the field at Stuttgart, AR in 1995 and 1996 for evaluation of growth, development, and physiological characteristics. Maximum plant heights ranged from 118 to 161 cm compared with 101 cm for the long-grain cultivar, Kaybonnet. Days to heading for these accessions ranged from 83 to 108 days compared with 96 days for Kaybonnet. As a group, awned blackhull accessions headed later than the awnless strawhull accessions. All red rice accessions except for a rice-red rice cross, KatyRR, experienced significant seed shattering before harvest. Chlorophyll content in red rice seedlings averaged 15% less than in Kaybonnet, accounting for the lighter green coloration of red rice. When expressed on a per leaf area basis, leaf transpiration and photosynthesis rates were similar for five diverse accessions of red rice, but were 12 to 13% less than for Kaybonnet. The relatively low leaf gas exchange values for red rice were consistent with their relatively lower chlorophyll contents compared to Kaybonnet. However, red rice’s low gas exchange rates per leaf area were more than compensated for by its greater production of tillers and total biomass which generally ranged between 2 and 3½ times that of Kaybonnet. Most of the red rice accessions were categorized as ‘medium-grain’ types based on their seed dimensions. This research quantified several key biological traits among distinct types of red rice and established baseline comparisons with commercial rice in Arkansas.