# Enhanced Early Detection and Precision Monitoring of Rubber Tree Powdery Mildew Pathogen Erysiphe quercicola Using Quantitative PCR and Droplet Digital PCR

## TL;DR

This paper introduces a new molecular method to detect and monitor a fungal disease in rubber trees, improving early detection and reducing the need for harmful chemicals.

## Contribution

The study introduces an integrated molecular detection platform combining qPCR, ddPCR, and PMA for enhanced detection of E. quercicola.

## Key findings

- The platform can detect E. quercicola at concentrations as low as 10 spores/mL and 10−5 ng/μL mycelial DNA.
- It distinguishes viable from non-viable spores and detects mycelia in asymptomatic leaves and aged lesions.
- The method helps assess fungicide efficacy and reduces chemical use and environmental impact.

## Abstract

Rubber trees are crucial to the global industrial economy, but they are facing the threat of powdery mildew caused by Erysiphe quercicola. Effective management of this disease depends on early detection. However, traditional monitoring methods are labor-intensive and often inaccurate. This limitation underscores the need for more precise and efficient techniques. This study developed and validated an integrated molecular detection platform that combines quantitative PCR (qPCR), droplet digital PCR (ddPCR), and propidium monoazide (PMA) treatments. The platform demonstrated a robust detection range, accurately quantifying E. quercicola at concentrations as low as 10 spores/mL spore DNA and 10−5 ng/μL mycelial DNA. Additionally, the system distinguished viable from non-viable spores and detected E. quercicola mycelia in both asymptomatic leaves and aged lesions, significantly enhancing early-stage detection and disease monitoring. This technology also helps assess the efficacy of fungicides against powdery mildew, potentially reducing the use of chemicals and their environmental impact. By improving early diagnosis and disease management, this approach promises to reduce dependence on fungicides and mitigate economic and environmental impacts, highlighting the enormous potential of advanced molecular technologies in sustainable agricultural practices in rubber plantations.