title: The triploid East African Highland Banana (EAHB) genepool is genetically uniform arising from a single ancestral clone that underwent population expansion by vegetative propagation.
abstract: All East African Highland Banana varieties are genetically uniform having arisen from a single clone introduced to Africa. East African Highland bananas (EAHBs) are a subgroup of triploid (AAA genome) bananas of importance to food security in the Great Lakes region of Africa. Little is known about their genetic variation, population structure and evolutionary history. Ninety phenotypically diverse EAHB cultivars were genotyped at 100 SSR microsatellite markers to investigate population genetic diversity, the correlation of genetic variability with morphological classes, and evolutionary origins since introduction to Africa. Population-level statistics were compared to those for plantain (AAB) and dessert (AAA) cultivars representing other M. acuminata subgroups. EAHBs displayed minimal genetic variation and are largely genetically uniform, irrespective of whether they were derived from the distinct Ugandan or Kenyan germplasm collections. No association was observed between EAHB genetic diversity and currently employed morphological taxonomic systems for EAHB germplasm. Population size dynamics indicated that triploid EAHBs arose as a single hybridization event, which generated a genetic bottleneck during foundation of the EAHB genepool. As EAHB triploids are sterile, subsequent asexual vegetative propagation of EAHBs allowed a recent rapid expansion in population size. This provided a basis for emergence of genetically near-isogenic somatic mutants selected across farmers and environments in East Africa over the past 2000 years since EAHBs were first introduced to the African continent.
authors.affiliation: Genetics and Biotechnology Lab, Plant and AgriBiosciences Research Centre (PABC), School of Natural Sciences, C306 Aras de Brun, National University of Ireland Galway, University Road, Galway, Ireland.|International Institute for Tropical Agriculture (IITA), Biosciences Eastern and Central Africa (BecA-ILRI), P.O. Box 30709-00100, Nairobi, Kenya.
authors.forename: Mercy
authors.initials: M
authors.lastname: Kitavi
authors.affiliation: School of Mathematics, Statistics and Applied Mathematics, National University of Ireland Galway, University Road, Galway, Ireland.
authors.forename: Tim
authors.initials: T
authors.lastname: Downing
authors.affiliation: International Institute for Tropical Agriculture (IITA), Biosciences Eastern and Central Africa (BecA-ILRI), P.O. Box 30709-00100, Nairobi, Kenya.|Bill and Melinda Gates Foundation, 500 5th Ave N, Seattle, WA, 98102, USA.
authors.forename: Jim
authors.initials: J
authors.lastname: Lorenzen
authors.affiliation: Bioversity International, PLOT 106, Katalima Road, P.O. Box 24384, Kampala, Uganda.
authors.forename: Deborah
authors.initials: D
authors.lastname: Karamura
authors.affiliation: Kenya Agricultural Research Institute (KARI), KARI, Kisii Centre, P.O. Box 523-40200, Kisii, Kenya.
authors.forename: Margaret
authors.initials: M
authors.lastname: Onyango
authors.affiliation: International Institute for Tropical Agriculture (IITA), Biosciences Eastern and Central Africa (BecA-ILRI), P.O. Box 30709-00100, Nairobi, Kenya.
authors.forename: Moses
authors.initials: M
authors.lastname: Nyine
authors.affiliation: International Institute for Tropical Agriculture (IITA), Biosciences Eastern and Central Africa (BecA-ILRI), P.O. Box 30709-00100, Nairobi, Kenya.
authors.forename: Morag
authors.initials: M
authors.lastname: Ferguson
authors.affiliation: Genetics and Biotechnology Lab, Plant and AgriBiosciences Research Centre (PABC), School of Natural Sciences, C306 Aras de Brun, National University of Ireland Galway, University Road, Galway, Ireland. charles.spillane@nuigalway.ie.
authors.forename: Charles
authors.identifier: http://orcid.org/0000-0003-3318-323X
authors.initials: C
authors.lastname: Spillane
mesh_terms: D054458:Amplified Fragment Length Polymorphism Analysis; D018744:DNA, Plant / Q000235:genetics; D019143:Evolution, Molecular; D005788:Gene Pool; D014644:Genetic Variation; D005828:Genetics, Population; D007630:Kenya; D018895:Microsatellite Repeats; D028521:Musa / Q000235:genetics*; D011156:Population Density; D057885:Triploidy; D014454:Uganda
chemical_list: D018744:DNA, Plant