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Research article - Peer-reviewed, 2021

Genomic Scan of Male Fertility Restoration Genes in a 'Gulzow' Type Hybrid Breeding System of Rye (Secale cereale L.)

Vendelbo, Nikolaj Meisner; Mahmood, Khalid; Sarup, Pernille; Kristensen, Peter Skov; Orabi, Jihad; Jahoor, Ahmed


Efficient and stable restoration of male fertility (Rf) is a prerequisite for large-scale hybrid seed production but remains an inherent issue in the predominant fertility control system of rye (Secale cereale L.). The 'Gulzow' (G)-type cytoplasmic male sterility (CMS) system in hybrid rye breeding exhibits a superior Rf. While having received little scientific attention, one major G-type Rf gene has been identified on 4RL (Rfg1) and two minor genes on 3R (Rfg2) and 6R (Rfg3) chromosomes. Here, we report a comprehensive investigation of the genetics underlying restoration of male fertility in a large G-type CMS breeding system using recent advents in rye genomic resources. This includes: (I) genome-wide association studies (GWAS) on G-type germplasm; (II) GWAS on a biparental mapping population; and (III) an RNA sequence study to investigate the expression of genes residing in Rf-associated regions in G-type rye hybrids. Our findings provide compelling evidence of a novel major G-type non-PPR Rf gene on the 3RL chromosome belonging to the mitochondrial transcription termination factor gene family. We provisionally denote the identified novel Rf gene on 3RL RfNOS1. The discovery made in this study is distinct from known P- and C-type systems in rye as well as recognized CMS systems in barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.). We believe this study constitutes a stepping stone towards understanding the restoration of male fertility in the G-type CMS system and potential resources for addressing the inherent issues of the P-type system.


restoration of male fertility (Rf); cytoplasmic male sterility (CMS); pentatricopeptide repeat protein (PPR); mitochondrial transcription termination factor (mTERF); 600K SNP array; genome-wide association study (GWAS); RNAseq; chi-square; linkage disequilibrium

Published in

International Journal of Molecular Sciences
2021, volume: 22, number: 17, article number: 9277
Publisher: MDPI

Authors' information

Vendelbo, Nikolaj Meisner
Aarhus University
Mahmood, Khalid
Nordic Seed A/S
Sarup, Pernille
Nordic Seed AS
Kristensen, Peter Skov
Nordic Seed AS
Orabi, Jihad
Nordic Seed A/S
Nordic Seed A/S
Swedish University of Agricultural Sciences, Department of Plant Breeding

UKÄ Subject classification

Agricultural Science

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