| Abstract Detail
Plant Biology in Sub-Saharan Africa Semon, Mande [1], Nielsen, Rasmus [2], Jones, Monty [3], McCouch, Susan [4]. The Evolutionary History of the African Rice Oryza glaberrima Steud. The relationship among seven rice species of the genome AA group namely cultivated African rice, Oryza glaberrima, and its two wild relatives (O. barthii and O. longistaminata), cultivated Asian rice, O. sativa, and two of its wild relatives (O. nivara and O. rufipogon), O. meriodinalis from Oceania and O. glumaepatula from the Americas were assessed with 10 chloroplast SSR loci located in chloroplast DNA (cpDNA). Using a coalescence-based approach, the species tree estimated supported the conclusion that rice species within continents were monophyletic. Low haplotype diversity was observed in O. glaberrima compared to its closest wild relative, O. barthii, contrasting to a much smaller difference between O. sativa and its wild relative, O. rufipogon, suggesting that there was a severe bottleneck in effective population size during the domestication of O. glaberrima. Furthermore, using 93 nuclear SSR markers, the relative importance of introgression, admixture, geography and ecological specialization in shaping the pattern of genetic variation within O. glaberrima were investigated. O. glaberrima has been cultivated in West Africa for more than 3,500 years and it has been sympatric to O. sativa for over 400 years. It is of interest to understand the population structure and evolution of this native African species. The structure analysis showed 3 cryptic sub-populations within the O. glaberrima species corresponding to ecological specialization and, an admixed population resulting from introgression to or from O. sativa. The conclusions of this study have practical implications for the management and breeding of domesticated rice species. Log in to add this item to your schedule
1 - Africa Rice Center (WARDA), 01 BP 2031 Cotonou, Benin republic, Africa 2 - Cornell University, Department of Biological Statistics and Computational Biology 3 - FARA, c/o FAO Regional office for Africa 4 - Cornell University, Department of Plant Breeding
Keywords: none specified
Presentation Type: ASPB Major Symposium Session: S02 Location: International Ballroom/Hilton Date: Sunday, July 8th, 2007 Time: 9:00 AM Number: S02001 Abstract ID:2568 |