Segmental allopolyploidy in action: Increasing diversity through polyploid hybridization and homoeologous recombination

Abstract

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.

Homoeologous Exchanges, Segmental Allopolyploidy, and Polyploid Genome Evolution

“…Reconciliation between the classic definition of segmental allopolyploids as "containing autopolyploid and allopolyploid segments" and modern genomic observations of genic synteny is, of course, provided by the mechanism of homoeologous exchange following allopolyploidy. A modern conception of "segmental allopolyploids" may thus include both transitional autopolyploids as well as allopolyploids that contain a mix of auto-and allopolyploid segments derived via homoeologous exchanges (duplication-deletion events; e.g., Sun et al, 2017;Leal-Bertioli et al, 2018;Bertioli et al, 2019). The dynamics of this process have now been described in numerous experimental systems.…”

Preferential Disomic Segregation and C. micrantha/C. medica Interspecific Recombination in Tetraploid ‘Giant Key’ Lime; Outlook for Triploid Lime Breeding

“…Overcoming this issue will require the production of large hybrid populations, as emphasized by Rouiss et al (2018). Leal-Bertioli et al (2018) successfully increased diversity in peanuts through polyploid hybridization and homoeologous recombination and highlighted the potential of segmental allotetraploids for plant breeding.…”

The genome sequence of segmental allotetraploid peanut Arachis hypogaea

“…These diploid genomes afforded new insights into peanut genetics. Notably, it was possible to infer that some chromosome ends of A. hypogaea had changed from the expected AABB structure to AAAA or BBBB, implying a particular complexity in peanut genetics 6,[15][16][17][18] .…”