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Segmental allopolyploidy in action: Increasing diversity through polyploid hybridization and homoeologous recombination
- Source :
- Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA-Alice), Empresa Brasileira de Pesquisa Agropecuária (Embrapa), instacron:EMBRAPA
- Publication Year :
- 2018
-
Abstract
- PREMISE OF THE STUDY The genetic bottleneck of polyploid formation can be mitigated by multiple origins, gene flow, and recombination among different lineages. In crop plants with limited origins, efforts to increase genetic diversity have limitations. Here we used lineage recombination to increase genetic diversity in peanut, an allotetraploid likely of single origin, by crossing with a novel allopolyploid genotype and selecting improved lines. METHODS Single backcross progeny from cultivated peanut × wild species-derived allotetraploid cross were studied over successive generations. Using genetic assumptions that encompass segmental allotetraploidy, we used single nucleotide polymorphisms and whole-genome sequence data to infer genome structures. KEY RESULTS Selected lines, despite a high proportion of wild alleles, are agronomically adapted, productive, and with improved disease resistances. Wild alleles mostly substituted homologous segments of the peanut genome. Regions of dispersed wild alleles, characteristic of gene conversion, also occurred. However, wild chromosome segments sometimes replaced cultivated peanut's homeologous subgenome; A. ipaensis B sometimes replaced A. hypogaea A subgenome (~0.6%), and A. duranensis replaced A. hypogaea B subgenome segments (~2%). Furthermore, some subgenome regions historically lost in cultivated peanut were "recovered" by wild chromosome segments (effectively reversing the "polyploid ratchet"). These processes resulted in lines with new genome structure variations. CONCLUSIONS Genetic diversity was introduced by wild allele introgression, and by introducing new genome structure variations. These results highlight the special possibilities of segmental allotetraploidy and of using lineage recombination to increase genetic diversity in peanut, likely mirroring what occurs in natural segmental allopolyploids with multiple origins.
- Subjects :
- 0106 biological sciences
0301 basic medicine
Pre-breeding
Lineage (genetic)
Arachis
Introgression
Plant Science
Biology
01 natural sciences
Genome
Polyploidy
03 medical and health sciences
Polyploid
Lineage recombination
Genetics
Gene conversion
Allele
Homologous Recombination
Ecology, Evolution, Behavior and Systematics
Alleles
Genetic diversity
Tetr
Peanuts
food and beverages
Genetic Variation
Fabaceae
030104 developmental biology
Population bottleneck
Segmental allotetraploid
Hybridization, Genetic
010606 plant biology & botany
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Journal :
- Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA-Alice), Empresa Brasileira de Pesquisa Agropecuária (Embrapa), instacron:EMBRAPA
- Accession number :
- edsair.doi.dedup.....88f139c79325a975e2525e57d87c773b