# Unlocking the genetic control of early seedling resistance to wheat powdery mildew through microphenomics

## TL;DR

This study uses a new technique called microphenomics to identify genes and genotypes that help wheat resist powdery mildew in its early stages.

## Contribution

The study introduces microphenomics for quantifying early wheat resistance to powdery mildew and identifies novel genetic markers and genotypes.

## Key findings

- Microphenomics revealed 57, 61, and 57 significant markers for three resistance parameters.
- Gene enrichment analysis identified 17 biological processes linked to resistance.
- Eight genotypes from Oman and the UK showed strong resistance and genetic diversity.

## Abstract

Powdery mildew is one of the most devastating diseases affecting wheat‐growing areas worldwide. The most effective strategy for managing this disease is through the cultivation of resistant genotypes.

In this study, early resistance was assessed in a set of 197 spring wheat genotypes using a novel Microphenomics approach. Parameters measured using this technique were: the number of micro‐colonies 48 h post‐infection (N48), the median colony area 72 h post‐infection (M72), and the area under the disease progress curve (AUDPC). No significant correlations were found among these parameters. Single‐locus and multi‐locus GWAS revealed 57, 61, and 57 significant markers associated with N48, M72, and AUDPC, respectively. These markers were located within 29, 42, and 34 genes, respectively. Gene enrichment analysis uncovered 17 biological processes (BP), 13 cellular components, and one molecular function pathway. The 17 BP pathways formed a single network controlled by five gene models. Eight genotypes were identified as highly resistant based on all evaluation parameters.

Microphenomics is a cutting‐edge technique that facilitates large‐scale quantification of the early, often critical stages of plant‐pathogen interactions, providing unprecedented insights into the infection process and enabling the discovery of new resistance mechanisms. SL and ML‐GWAS, along with gene enrichment analysis, provided a deeper understanding of the genetic control of WPM early resistance. Genotypes from Oman and the UK were particularly notable as good sources for improving early resistance to wheat powdery mildew due to their superior response and the high genetic distance between them and the German genotypes. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Microphenomics is a new technique for detecting the very early resistance of powdery mildew in wheat seedlings, after 24, 48, and 72 h from infection. A number of 29, 42, and 34 genes models were identified to harbor significant SNP markers associated with the early resistance to WPM. The gene enrichment analysis of these gene models confirms their association with the resistance. Genotypes from Oman and the UK were notable as good sources for improving early resistance to WPM.