dc.contributor.author | Wolfe, M.D. |
dc.contributor.author | Bauchet, G.J. |
dc.contributor.author | Chan, A.W. |
dc.contributor.author | Lozano, R. |
dc.contributor.author | Ramu, P. |
dc.contributor.author | Egesi, C. |
dc.contributor.author | Kawuki, R. |
dc.contributor.author | Kulakow, P. |
dc.contributor.author | Rabbi, I. |
dc.contributor.author | Jannink, J.L. |
dc.date.accessioned | 2019-12-04T11:39:08Z |
dc.date.available | 2019-12-04T11:39:08Z |
dc.date.issued | 2019-10 |
dc.identifier.citation | Wolfe, M.D., Bauchet, G.J., Chan, A.W., Lozano, R., Ramu, P., Egesi, C., ... & Jannink, J.L. (2019). Historical introgressions from a wild relative of modern cassava improved important traits and may be under balancing selection. Genetics, 213(2), 1-15. |
dc.identifier.issn | 0016-6731 |
dc.identifier.uri | https://hdl.handle.net/20.500.12478/6544 |
dc.description | Published online: 17 Oct 2019 |
dc.description.abstract | Introgression of alleles from wild relatives has often been adaptive in plant breeding. However, the significance of historical hybridization events in modern breeding is often not clear. Cassava (Manihot esculenta) is among the most important staple foods in the world, sustaining hundreds of millions of people in the tropics, especially in sub-Saharan Africa. Widespread genotyping makes cassava a model for clonally-propagated root and tuber crops in the developing world and provides an opportunity to study the modern benefits and consequences of historical introgression. We detected large introgressed M. glaziovii genome-segments in a collection of 2742 modern cassava landraces and elite germplasm, the legacy of 1930's era breeding to combat disease epidemics . African landraces and improved varieties were on average 3.8% (max 13.6% ) introgressed. Introgressions accounted for significant (mean 20% , max 56% ) portion of the heritability of tested traits. M. glaziovii alleles on the distal 10Mb of chr. 1 increased dry matter and root number. On chr. 4, introgressions in a 20Mb region improved harvest index and brown streak disease tolerance. We observed the introgression frequency on chr. 1 double over three cycles of selection and that later stage trials selectively excluded homozygotes from consideration as varieties. This indicates a heterozygous advantage of introgressions. However, we also found that maintaining large recombination-suppressed introgressions in the heterozygous state allowed the accumulation of deleterious mutations. We conclude that targeted recombination of introgressions would increase the efficiency of cassava breeding by allowing simultaneous fixation of beneficial alleles and purging of genetic load. |
dc.format.extent | 1-15 |
dc.language.iso | en |
dc.rights | Copyrighted; all rights reserved |
dc.subject | Cassava |
dc.subject | Introgression |
dc.subject | Genetics |
dc.subject | Heterozygotes |
dc.subject | Breeding |
dc.subject | Africa South Of Sahara |
dc.title | Historical introgressions from a wild relative of modern cassava improved important traits and may be under balancing selection |
dc.type | Journal Article |
dc.description.version | Peer Review |
cg.contributor.crp | Roots, Tubers and Bananas |
cg.contributor.affiliation | Cornell University |
cg.contributor.affiliation | Boyce Thompson Institute |
cg.contributor.affiliation | National Root Crops Research Institute, Nigeria |
cg.contributor.affiliation | National Root Crops Resources Research Institute, Uganda |
cg.contributor.affiliation | International Institute of Tropical Agriculture |
cg.contributor.affiliation | United States Department of Agriculture |
cg.coverage.region | Africa |
cg.coverage.region | East Africa |
cg.coverage.region | West Africa |
cg.coverage.country | Nigeria |
cg.coverage.country | Uganda |
cg.creator.identifier | Chiedozie Egesi: 0000-0002-9063-2727 |
cg.creator.identifier | Peter Kulakow: 0000-0002-7574-2645 |
cg.creator.identifier | Ismail Rabbi: 0000-0001-9966-2941 |
cg.creator.identifier | Jean-Luc Jannink: 0000-0003-4849-628X |
cg.researchtheme | BIOTECH & PLANT BREEDING |
cg.isijournal | ISI Journal |
cg.authorship.types | CGIAR and developing country institute |
cg.iitasubject | Agronomy |
cg.iitasubject | Cassava |
cg.iitasubject | Plant Breeding |
cg.journal | Genetics |
cg.howpublished | Formally Published |
cg.accessibilitystatus | Limited Access |
local.dspaceid | 109968 |
cg.targetaudience | Scientists |
cg.identifier.doi | https://dx.doi.org/10.1534/genetics.119.302757 |