Submitted to: Arkansas Experiment Station Research Series
Publication Type: Experiment Station
Publication Acceptance Date: August 1, 2000
Publication Date: N/A
Interpretive Summary: Interpretive summary not required.
Technical Abstract: Red rice (Oryza sativa L.) is an economically important weed in many rice production areas in the southern United States, and increasingly, throughout the world. Rice blast (Pyricularia grisea), the most problematic disease of rice in the United States, can attack red rice as well as rice. A collection of 160 red rice entries from Arkansas and other rsouthern rice producing states were evaluated for relative susceptibility to races IB-49, IC-17, IE-1K, IG-1 and IH-1 of the rice blast fungus in greenhouse tests. Four red rice entries tested were resistant to all five races. None of the red rice entries were susceptible to all the blast races. Obvious differences in distribution of major gene blast resistance were evident in that 90, 80, 30, 28 and 14 percent of the red rice entries were resistant or moderately resistant to races IC-17, IG-1, IE-1K, IH-1 and IB-49, respectively, and suggest either a natural selection for blast tolerance at sites of origin or natural interbreeding with white rice resulting from the close cultural association. This data may be useful in developing control strategies for red rice, in the eventual identification and transfer of disease resistance genes from red rice into rice, in acquiring a better understanding about overwintering of the blast fungus, and in learning about the natural transfer of genes between wild red rices and cultivated white rices.