Submitted to: Rice Technical Working Group Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 1/15/2008
Publication Date: 3/1/2008
Citation: Brooks, S.A., Yan, W., Jackson, A.K., Deren, C.W. 2008. Rc-g: A new allele for red pericarp discovered in cultivated rice. In: Proceedings of the 32nd Rice Technical Working Group Meetings, February 18-21, 2008, San Diego, CA. 2008. CDROM.
Technical Abstract: The occurrence of grain with red pericarp in rice production is normal where red rice is a common weed problem. Classic weedy red rice can usually be distinguished morphologically without the need to de-hull seed to reveal pericarp color. However, rice with red pericarp is also found in cultivated grain types and has typically been attributed to outcrosses of cultivated rice to red rice. Recently, typical long grains with red pericarp were identified at very low frequency in a seed lot of the cultivar ‘Wells’. The goal of this project was to fully characterize red-pericarp-Wells and determine the source of red pericarp in these seeds. The Rc locus regulates pigmentation of the rice bran layer, and selection for the rc allele (white pericarp) is ubiquitous among cultivated rice varieties. Using molecular markers and DNA sequence for the Rc locus we demonstrated that red pericarp in Wells was not the result of an outcross or seed mixture. We identified a new allele that arose by natural mutation within the rc pseudogene. The mutation restored the reading frame of the gene, and reverted the bran layer pigmentation to red (wild-type). Using DNA sequence and linkage analysis we were able to demonstrate that mutation within rc resulted in the new, dominant, wild-type allele Rc-g.