Association Mapping of Fertility Restorer Gene for CMS PET1 in Sunflower

Denis Goryunov,Denis Goryunov,Artemy Shumskiy,Nikolai Benko,Yakov Demurin,Stepan Boldyrev,Stepan Boldyrev,Elena Gurchenko,Rim Gubaev,Elena Martynova,Daria Petrova,Irina Anisimova,Evgeniia Sotnikova,Asiya Ayupova,Svetlana Goryunova,Zhanna Mukhina,Philipp Khaitovich,Alina Chernova,Sergey Garkusha,Pavel Mazin,Vera Gavrilova

doi:10.3390/agronomy9020049

Abstract

The phenomenon of cytoplasmic male sterility (CMS), consisting in the inability to produce functional pollen due to mutations in mitochondrial genome, has been described in more than 150 plant species. With the discovery of nuclear fertility restorer (Rf) genes capable of suppressing the CMS phenotype, it became possible to use the CMS-Rf genetic systems as the basis for practical utilization of heterosis effect in various crops. Seed production of sunflower hybrids all over the world is based on the extensive use of the PET1 CMS combined with the Rf1 gene. At the same time, data on Rf1 localization, sequence, and molecular basis for the CMS PET1 type restoration of fertility remain unknown. Searching for candidate genes of the Rf1 gene has great fundamental and practical value. Therefore, in this study, association mapping of fertility restorer gene for CMS PET1 in sunflower was performed. The genome-wide association study (GWAS) results made it possible to isolate a segment 7.72 Mb in length on chromosome 13, in which 21 candidates for Rf1 fertility restorer gene were identified, including 20 pentatricopeptide repeat (PPR)family genes and one Probable aldehyde dehydrogenase gene. The results will serve as a basis for further study of the genetic nature and molecular mechanisms of pollen fertility restoration in sunflower, as well as for further intensification of sunflower breeding.

Highlights

The phenomenon of cytoplasmic male sterility, consisting in the inability to produce functional pollen due to mutations in mitochondrial genome, has been described in more than 150 plant species [1,2,3]
Restriction site associated DNA sequencing (RAD) libraries were prepared using HindIII and Nlalll endonucleases as previously described [32] with minor modifications and sequenced in Illumina
Statistical analysis using the mixed linear models (MLMs) [38] implemented in the Tassel 5 software was performed for association mapping with Principal component analysis (PCA) and kinship matrixes as covariates

Summary

Introduction

The phenomenon of cytoplasmic male sterility, consisting in the inability to produce functional (viable) pollen due to mutations in mitochondrial genome, has been described in more than 150 plant species [1,2,3]. Various authors distinguish from one to five genes responsible for the restoration of pollen fertility in CMS PET1 [8,9]. Seed production of sunflower hybrids is based on the extensive use of the Rf1 and Rf2 genes, which by interacting with each other give the effect of restoring pollen fertility. An exceptionally high rate of evolution of the subfamily of RFL-PPR genes [29,30], as well as the important role of CMS and restoration of fertility in the formation of new species [31] allow us to consider them as a source of molecular markers for phylogenetic research. In this study, association mapping of fertility restorer gene for CMS PET1 in sunflower was performed

Materials and Methods

Genotyping and GWAS Analysis

Identification of Rf1 Candidate Genes

Pairwise