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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Mycology and Nematology Genetic Diversity and Biology Laboratory » Research » Research Project #443686

Research Project: Finding the Origin of Litylenchus Crenatae Mccanni, the Invasive Nematode Causing Widespread Decline of American Beech

Location: Mycology and Nematology Genetic Diversity and Biology Laboratory

Project Number: 8042-22000-322-011-I
Project Type: Interagency Reimbursable Agreement

Start Date: Apr 1, 2023
End Date: Apr 1, 2026

Objective:
Given the importance of Fagus grandifolia (American beech) to eastern forests, and the rapid range expansion we have witnessed of beech leaf disease and its causal nematode, Litylenchus crenatae mccanni, critical gaps in our understanding of this disease and the biology of the causal nematode must be addressed. Among these, and central to this proposal, is the goal of identifying the origin – both geographic and host – of this invasive, and presumably exotic, nematode. 1. Population structure of Litylenchus crenatae mccanni in North America. Species-specific microsatellites to assess pathways of spread of this nematode in North America. 2. Expedition to Japan to evaluate the diversity of the closest nematode subspecies (Litylenchus crenatae crenatae) in Japan. 3. Population structure of Litylenchus crenatae crenatae in Japan. 4. Generate new transcriptomic data for both nematode subspecies.

Approach:
1. Population structure of Litylenchus crenatae mccanni in North America: a. Infected beech strands will be sampled for buds and/or leaves from OH, NY, PA, WV, VA, CT, MA, NH, and ME. b. Individual nematodes extracted from buds and/or leaves will be processed individually for DNA. DNA will be use for genotyping and analysis. 2. Expedition to Japan to evaluate the diversity of the closest nematode subspecies: a. Collect buds and leaves from Fagus species – native and planted -- that are characteristically symptomatic. b. Use morphology and universal molecular markers (e.g., sequencing of ITS, 18S and 28S rRNA regions, and COI gene fragments) to ascertain nematode species and subspecies. 3. Population structure of Litylenchus crenatae crenatae in Japan: a. Individual nematodes extracted from buds and/or leaves will be processed individually for DNA. DNA will be use for genotyping and analysis. 4. New transcritptome data: total nematode mRNA will be use for generating new mRNA-seq libraries.