Identification of QTLs for Rust Resistance in the Peanut Wild Species Arachis magna and the Development of KASP Markers for Marker-Assisted Selection

Abstract

Rust is a major pathogen of the peanut crop. Development and adoption of rust-resistant cultivars is the most cost efficient and effective way to control the spread of the disease and reduce yield losses. Some cultivated peanut germplasm accessions have a degree of resistance, but the secondary gene pool is a source of much stronger resistance alleles. Wild species, however, have undesirable agronomic traits that are a disincentive to their use in breeding. The identification of genomic regions that harbor disease resistance in wild species is the first step in the implementation of marker-assisted selection that can speed the introgression of wild disease resistances and the elimination of linkage drag. In this work, we identify genome regions that control different components of rust resistance in a recombinant inbred line population developed from a cross between two Arachis species, the susceptible most probable B genome ancestor of cultivated peanut, Arachis ipaënsis, and an accession of its closest relative, Arachis magna, which is resistant to rust. Quantitative trait loci for several components of resistance were placed in the same position on linkage group B08. Single-nucleotide polymorphism Kompetitive allele-specific polymerase chain reaction markers for rust resistance region were designed and validated for marker function in both diploid and tetraploid contexts.

Comparison ofArachis monticolawith Diploid and Cultivated Tetraploid Genomes Reveals Asymmetric Subgenome Evolution and Improvement of Peanut

“…RLPs are significantly enriched in A08 (Figure a), which may result from frequent rearrangement events between A08 and A07 . QTLs are associated with resistance regions of nematode resistance, root‐knot nematode (RKN) (Meloidogyne arenaria (Neal) Chitwood) resistance, rust resistance, and late leaf spot resistance . Interestingly, we found 14 QTLs close to RGA‐enriched regions (Table S17, Supporting Information).…”

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

“…Since peanut rust ( Puccinia arachidis ) was not consistently found in the field, detached leaf assays were conducted as described by Leal‐Bertioli et al. () using rust uredospores collected from infested field‐grown susceptible plants. Resistance was evaluated as incubation period, total number of lesions, and sporulating lesions per leaf area.…”

Target Amplicon Sequencing for Genotyping Genome‐Wide Single Nucleotide Polymorphisms Identified by Whole‐Genome Resequencing in Peanut

“…Consequently, the inheritance of traits related to oil components, as well as other agronomically important traits, is very complex. Over the last decade, genetic studies of peanut have advanced greatly: DNA markers were developed (Pandey et al, 2012); molecular genetic maps were established (Gautami et al, 2012; Shirasawa et al, 2013); and quantitative trait loci (QTL) were identified for agronomically important traits including oil components (Shirasawa et al, 2012; Leal‐Bertioli et al, 2015; Kolekar et al, 2016). These resources can be used as tools for DNA marker‐assisted selection to accelerate breeding programs in peanut as in other crop species (Perez‐de‐Castro et al, 2012).…”