Location: Corn Insects and Crop Genetics ResearchTitle: The genome sequences of Arachis duranensis and Arachis ipaensis, the diploid ancestors of cultivated peanut Author
Submitted to: Nature Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/29/2016
Publication Date: 2/22/2016
Citation: Bertioli, D., Cannon, S.B., Froenicke, L., Huang, G., Farmer, A.D., Cannon, E., Dash, S., Liu, X., Barkley, N.L., Guo, B., Scheffler, B.E., et al. 2016. The genome sequences of Arachis duranensis and Arachis ipaensis, the diploid ancestors of cultivated peanut. Nature Genetics. 48:438-446. doi: 10.1038/ng.3517. Interpretive Summary: Peanut is very important in human nutrition, providing a calorie-dense, versatile, high-protein food source - one that is especially unusual in that it is palatable without cooking or preparation. An international consortium of researchers, with key USDA-ARS participation, has sequenced the genomes of the two closest wild ancestors of cultivated peanut. Those ancestors merged to form a new species, which was domesticated to become modern cultivated peanut. An important finding of this research is that the unusual hybridization of these two species was likely the direct result of early agriculturalists in South America. The genome sequences from these wild species thus comprise essentially all of the genetic material from the modern cultivated peanut. This research will be used by plant researchers and breeders to more efficiently select improved peanut varieties, and to speed development of varieties that are well suited for growing in various regions of the world. The genome sequence has already been useful in helping identify mechanisms for resistance to root-knot nematodes and rust (a fungal disease), which are serious challenges for many peanut farmers.
Technical Abstract: Cultivated peanut (Arachis hypogaea) is an allotetraploid with closely related subgenomes of total size ~2.7 Gb. This makes assembly of chromosomal pseudomolecules very challenging. Here we report genome sequences of cultivated peanut’s diploid ancestors (A. duranensis and A. ipaënsis). We show they are similar to cultivated peanut’s A- and B-genomes and use them to identify candidate disease resistance genes, create improved tetraploid transcript assemblies, and detect genetic exchange between peanut’s subgenomes. Based on remarkably high DNA identity and biogeography, we conclude that A. ipaënsis may be a direct descendant of the same population that contributed the B-genome to cultivated peanut.