# Genetic analysis of a quantitative trait locus associated with resistance to the root-lesion nematode Pratylenchus neglectus in triticale

## TL;DR

A genetic region in triticale linked to resistance against a harmful nematode was identified, offering new potential for improving wheat resistance.

## Contribution

The first mapped QTL for root-lesion nematode resistance in triticale is reported.

## Key findings

- A QTL on rye-derived chromosome 5R explains 20% of resistance variance to Pratylenchus neglectus in triticale.
- A high-throughput KASP assay was developed for rapid genotyping of the resistance allele.
- This QTL provides a foundation for transferring resistance into wheat via marker-assisted selection.

## Abstract

Message.

A QTL from rye chromosome 5R confers resistance to root-lesion nematode in triticale.

Root-lesion nematode (Pratylenchus neglectus, RLN) poses a significant threat to global wheat production. High levels of RLN resistance are rare in wheat. Triticale, an amphiploid generated by combining wheat and rye genomes that naturally carries rye-derived defense alleles, offers an untapped reservoir of nematode resistance. Here, we evaluated the response to RLN in 137 recombinant inbred lines (RILs) derived from a cross between two triticale cultivars: Siskiyou (susceptible) and Villax St. Jose (resistant). Genotyping-by-sequencing identified 1054 high-quality single-nucleotide polymorphism (SNP) markers, which, along with seven simple sequence repeat (SSR) markers, were assembled into 21 linkage groups covering the triticale genome. A single quantitative trait locus (QTL) on the rye-derived chromosome 5R was identified that explained approximately 20% of the phenotypic variance across experiments. A high-throughput Kompetitive allele-specific PCR (KASP) assay based on the most significant SNP marker was developed, providing a rapid genotyping platform for selecting the resistance allele and reducing reliance on labor-intensive phenotyping for P. neglectus resistance in triticale. This study reports the first mapped RLN-resistance QTL in triticale, laying the fundamental foundation for introgressing the 5R resistance allele into wheat via marker-assisted selection combined with chromosome engineering, thereby broadening the genetic basis for nematode resistance in cereal crops.

The online version contains supplementary material available at 10.1007/s00122-025-05112-6.