rice

The history of rice domestication has long been a subject of debate. Recently obtained genetic evidence provides new insights into this complex story.

Genome-wide studies of variation demonstrate that the two varietal groups in Oryza sativa (indica and japonica) arose from genetically distinct gene pools within a common wild ancestor, Oryza rufipogon, suggesting multiple domestications of O. sativa.

However, the evolutionary history of recently cloned domestication genes adds another layer of complexity to the domestication of rice.

Although some alleles exist only within specific subpopulations, as would be expected if the domestications occurred independently, other major domestication alleles are common to all cultivated O. sativa varieties.

Current view of rice domestication supports multiple domestications coupled with limited introgression that transferred key domestication alleles between divergent rice gene pools.

References

 Paleogenomic analysis of the short arm of chromosome 3 reveals the history of the african and asian progenitors of cultivated rices. Roulin A, Chaparro C, Piégu B, Jackson S, Panaud O. Genome Biol Evol. 2010 Feb 11;2010:132-9. PMID: 20333229

 Kovach MJ, Sweeney MT, McCouch SR. New insights into the history of rice domestication. Trends Genet. 2007 Nov;23(11):578-87. PMID: 17963977

 Lu J, Tang T, Tang H, Huang J, Shi S, Wu CI. The accumulation of deleterious mutations in rice genomes: a hypothesis on the cost of domestication. Trends Genet. 2006 Mar;22(3):126-31. PMID: 16443304