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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Genetic Improvement for Fruits & Vegetables Laboratory » Research » Research Project #438793

Research Project: Survey of Beneficial Endophytic Fungi in the Potato Endobiome

Location: Genetic Improvement for Fruits & Vegetables Laboratory

Project Number: 8042-21000-283-022-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Sep 1, 2020
End Date: Aug 30, 2022

Overall objective is to gain an understanding of the impact endophytic microbes have on potato foliar diseases. Individual objectives are 1. Survey the endobiome of two commonly grown potato cultivars of the same field generation at unique physiological growth stages, and 2. Comparison with contrasting generations (field year one versus field year six).

Determining endophytic fungal populations. Sampling will involve selecting undamaged leaves, removal of exterior microbes by surface sterilization in ethanol and bleach dips, followed by rinsing in sterile water. One-centimeter sections will be cut from the leaf and plated onto selective media that allows fungal growth. Initial interest will be on fungal endophytes. Individual isolates will be sub-cultured and identified microscopically and/or through 18S sequence analysis. Total fungal endophyte populations will also be analyzed from leaf tissue that has been thoroughly rinsed to remove superficial microbes, followed by total DNA extraction. DNA samples will be sequenced using a Nanopore MinIon. Comparisons will be made between cultured and total DNA samples to determine if some fungi are missing from either method of analysis. Sample selections. Two cultivars, Russet Burbank and Goldrush will be sampled at one month after emergence, at tuber initiation and approximately one month before maturity, selecting mature leaves at the bottom on third of the plants. This will provide information on fluctuations in endophyte populations through the growing season and determine if populations change as potatoes become more susceptible to foliar infections. Another sample set will be taken one week before and one week after the first fungicide application to determine the impact of fungicides on endophytic fungal populations.