Genome wide association studies in yam reveal the challenge of high heterozygosity

Yam (Dioscorea spp.) is a herbaceous vine crop valued for its starchy tubers, which are rich in essential nutrients. Its genome is highly heterozygous, contributing to considerable genetic diversity and adaptability. Understanding the polymorphism information content (PIC) of genetic markers is crit...

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Autores principales: Agre, A.P., Darkwa, K., Kohtaro, I., Matsumoto, R., Asfaw, A.
Formato: Journal Article
Lenguaje:Inglés
Publicado: 2025
Materias:
Acceso en línea:https://hdl.handle.net/10568/176487
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author Agre, A.P.
Darkwa, K.
Kohtaro, I.
Matsumoto, R.
Asfaw, A.
author_browse Agre, A.P.
Asfaw, A.
Darkwa, K.
Kohtaro, I.
Matsumoto, R.
author_facet Agre, A.P.
Darkwa, K.
Kohtaro, I.
Matsumoto, R.
Asfaw, A.
author_sort Agre, A.P.
collection Repository of Agricultural Research Outputs (CGSpace)
description Yam (Dioscorea spp.) is a herbaceous vine crop valued for its starchy tubers, which are rich in essential nutrients. Its genome is highly heterozygous, contributing to considerable genetic diversity and adaptability. Understanding the polymorphism information content (PIC) of genetic markers is critical for enhancing key agronomic traits such as yield. In this study, we conducted a genome-wide association analysis that accounts for heterozygosity to investigate fresh tuber yield variation in white Guinea yam (Dioscorea rotundata Poir). A total of 173 genotypes including 86 elite breeding clones, 77 genebank accessions, and 10 farmer varieteies were genotyped through whole-genome resequencing, yielding approximately 1.6 million single nucleotide polymorphism (SNP) markers. Association analysis was performed using a multi-locus mixed linear model (MLM), incorporating kinship matrices derived from marker subsets grouped by PIC levels (≤ 0.1, 0.1–0.2, 0.2–0.4, and > 0.4), alongside population structure. The analysis revealed that high-PIC markers had greater influence on trait associations. Twelve stable SNPs were significantly associated with fresh tuber yield. Functional annotation of these markers revealed putative genes related to plant growth and cellular regulation. Notably, markers located in heterozygosity-rich genomic regions were linked to high-yielding genotypes, while those in homozygous regions were associated with lower yields. These findings underscore the potential of PIC-based marker selection and highlight the value of integrating heterozygosity metrics into genomic-assisted breeding strategies for improving fresh tuber yield in white Guinea yam.
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spelling CGSpace1764872025-11-11T11:08:33Z Genome wide association studies in yam reveal the challenge of high heterozygosity Agre, A.P. Darkwa, K. Kohtaro, I. Matsumoto, R. Asfaw, A. yams dioscorea mapping yields heterozygotes forecasting Yam (Dioscorea spp.) is a herbaceous vine crop valued for its starchy tubers, which are rich in essential nutrients. Its genome is highly heterozygous, contributing to considerable genetic diversity and adaptability. Understanding the polymorphism information content (PIC) of genetic markers is critical for enhancing key agronomic traits such as yield. In this study, we conducted a genome-wide association analysis that accounts for heterozygosity to investigate fresh tuber yield variation in white Guinea yam (Dioscorea rotundata Poir). A total of 173 genotypes including 86 elite breeding clones, 77 genebank accessions, and 10 farmer varieteies were genotyped through whole-genome resequencing, yielding approximately 1.6 million single nucleotide polymorphism (SNP) markers. Association analysis was performed using a multi-locus mixed linear model (MLM), incorporating kinship matrices derived from marker subsets grouped by PIC levels (≤ 0.1, 0.1–0.2, 0.2–0.4, and > 0.4), alongside population structure. The analysis revealed that high-PIC markers had greater influence on trait associations. Twelve stable SNPs were significantly associated with fresh tuber yield. Functional annotation of these markers revealed putative genes related to plant growth and cellular regulation. Notably, markers located in heterozygosity-rich genomic regions were linked to high-yielding genotypes, while those in homozygous regions were associated with lower yields. These findings underscore the potential of PIC-based marker selection and highlight the value of integrating heterozygosity metrics into genomic-assisted breeding strategies for improving fresh tuber yield in white Guinea yam. 2025 2025-09-15T11:33:01Z 2025-09-15T11:33:01Z Journal Article https://hdl.handle.net/10568/176487 en Open Access application/pdf Agre, A.P., Darkwa, K., Kohtaro, I., Matsumoto, R. & Asfaw, A. (2025). Genome wide association studies in yam reveal the challenge of high heterozygosity. Scientific Reports, 15(1): 26929, 1-14.
spellingShingle yams
dioscorea
mapping
yields
heterozygotes
forecasting
Agre, A.P.
Darkwa, K.
Kohtaro, I.
Matsumoto, R.
Asfaw, A.
Genome wide association studies in yam reveal the challenge of high heterozygosity
title Genome wide association studies in yam reveal the challenge of high heterozygosity
title_full Genome wide association studies in yam reveal the challenge of high heterozygosity
title_fullStr Genome wide association studies in yam reveal the challenge of high heterozygosity
title_full_unstemmed Genome wide association studies in yam reveal the challenge of high heterozygosity
title_short Genome wide association studies in yam reveal the challenge of high heterozygosity
title_sort genome wide association studies in yam reveal the challenge of high heterozygosity
topic yams
dioscorea
mapping
yields
heterozygotes
forecasting
url https://hdl.handle.net/10568/176487
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AT matsumotor genomewideassociationstudiesinyamrevealthechallengeofhighheterozygosity
AT asfawa genomewideassociationstudiesinyamrevealthechallengeofhighheterozygosity