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ARS Home » Southeast Area » Tifton, Georgia » Crop Genetics and Breeding Research » Research » Publications at this Location » Publication #382361
Research Project: Development of High-Yielding, High-Oleic Peanut Cultivars or Germplasm with Tolerance to Biotic and Abiotic Stresses

Location: Crop Genetics and Breeding Research

Title: Homoeologous recombination is recurrent in the nascent synthetic allotetraploid Arachis ipaensis x Arachis correntina and its derivatives

Author
item CHU, Y - University Of Georgia
item BERTIOLI, D - University Of Georgia
item LEVINSON, C - University Of Georgia
item STALKER, H - North Carolina State University
item Holbrook, Carl - Corley
item OZIAS-AKINS, P - University Of Georgia

Submitted to: G3, Genes/Genomes/Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/21/2021
Publication Date: 3/8/2021
Citation: Chu, Y., Bertioli, D., Levinson, C., Stalker, H.T., Holbrook Jr, C.C., Ozias-Akins, P. 2021. Homoeologous recombination is recurrent in the nascent synthetic allotetraploid Arachis ipaensis x Arachis correntina and its derivatives. G3, Genes/Genomes/Genetics. 11(4):1-13. https://doi.org/10.1093/g3journal/jkab066.
DOI: https://doi.org/10.1093/g3journal/jkab066

Interpretive Summary: Cultivated peanut is an allotetraploid that originated from a natural cross between two diploid wild species and a spontaneous doubling of the chromosomes to restore fertility. This created a strong genetic bottleneck resulting in a narrow genetic base for cultivated peanut. Synthesis of new wild species-derived allotetraploids offers the opportunity to broaden the gene pool of peanut; however, the dynamics among the newly merged genomes creates predictable and unpredictable variation. We created and studied new allotetraploids to better understand this genetic vatiation. From a breeding perspective our observations offer both possibilities and perils; recombination between genomes increases genetic diversity, but genome instability could lead to instability of traits or even loss of viability within lineages.

Technical Abstract: Genome instability in newly synthesized allotetraploids has breeding implications that have not been fully appreciated. Synthesis of wild species-derived neotetraploids offers the opportunity to broaden the gene pool of peanut; however, the dynamics among the newly merged genomes creates predictable and unpredictable variation. Selfed progenies from the neotetraploid [A. ipaensis x A. correntina]4x and F1 hybrids and F2 progenies from crosses between A. hypogaea x [A. ipaensis x A. correntina]4x were genotyped by the Axiom Arachis 48K SNP array. Homoeologous recombination between the A. ipaensis and A. correntina derived subgenomes was observed in the S0 generation. Among the S1 progenies, these recombined segments segregated and new events of homoeologous recombination emerged. The genomic regions undergoing homoeologous recombination segregated mostly disomically in the F2 progenies from A. hypogaea x [A. ipaensis x A. correntina]4x crosses. New homoeologous recombination events also occurred in the F2 population, mostly found on chromosomes 03, 04, 05, and 06. From the breeding perspective, these phenomena offer both possibilities and perils; recombination between genomes increases genetic diversity, but genome instability could lead to instability of traits or even loss of viability within lineages.