Location: Crops Pathology and Genetics Research
Project Number: 2032-22000-017-071-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 15, 2025
End Date: Sep 14, 2026
Objective:
The objective of this project is to develop genomic and experimental resources for Polystigma amygdalinum, an emerging obligate biotrophic pathogen causing red leaf blotch in almond. The project aims to: (1) generate a high-quality genome assembly using long-read sequencing of infected leaf tissues; (2) conduct transcriptome sequencing from distinct infection stages to support gene prediction and identify infection-related genes; (3) develop an in vitro pathosystem for controlled studies of infection dynamics and fungicide efficacy.
Approach:
To achieve the objectives, high-molecular-weight DNA will be extracted from infected almond leaves and sequenced using long-read technology, followed by polishing with short-read sequencing. Total RNA will be extracted from lesion centers, margins, and uninfected tissues, and sequenced to support gene prediction and expression analysis. Host-derived sequences will be computationally removed. An in vitro pathosystem will be developed by testing various almond cultivars and spore types under controlled conditions to establish reproducible infection. The Cooperator will assist with field collection, molecular work, and data analysis.