Submitted to: Temperate Rice Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 1/9/2003
Publication Date: 3/10/2003
Citation: Gealy, D.R., Yan, W., Rutger, J.N. 2003. CHARACTERIZATION OF HYBRID POPULATIONS FROM RICE CROSSED WITH AWNED AND AWNLESS RED RICE. Temperate Rice Conference Proceedings. p. 69. Interpretive Summary:
Technical Abstract: Red rice (Oryza sativa L.) is a major weed of rice (Oryza sativa L.) in the southern U.S. and it intercrosses at low rates with the rice cultivars produced in this region. Knowledge of the plant phenotypes produced from such crosses may help farmers to accurately identify and manage crosses derived from specific red rice ecotypes and rice, including herbicide-resistant cultivars. F1 hybrids were produced by hand-pollinating male-sterile Kaybonnet and Cypress (southern long grain tropical japonica cultivars) with two awned and two awnless U.S. red rice types. Parental, F1, and F2 (>150) plants from these crosses were grown in the field under flooded conditions in 2002 at Stuttgart, AR. Phenotypic characteristics including tillering, tiller angle, leaf pubescence, culm and leaf color, plant height, days to flowering, awn length, hull color, and bran color were determined. F1 plants produced pubescent leaves and red bran color, confirming that these were dominant traits. The awned red rice crosses resulted in F1 plants with reddish-purple culms (not expressed in any of the parents) and flowering dates similar to both parents. Crosses with awnless Stuttgart strawhull red rice resulted in F1 plants with green culms and flowering dates later than either parent. Many F2 plants produced few or no seed, apparently because of sterility or because maturity was delayed to the point that heading and/or seed fill did not occur. F2 segregation ratios for phenotypic traits are being determined. Implications for identification and management of hybrid populations will be discussed.