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ARS Home » Southeast Area » Charleston, South Carolina » Vegetable Research » Research » Research Project #437518

Research Project: A Multi-state Effort to Contain and Manage the Invasive Guava Root Knot Nematode (GRKN) in Vegetable Crops.

Location: Vegetable Research

Project Number: 6080-22000-029-025-R
Project Type: Reimbursable Cooperative Agreement

Start Date: Oct 1, 2019
End Date: Aug 31, 2022

Objective:
To Evaluate and develop vegetable germplasm with resistance against the guava root knot nematode (Meloidogyne enterolobii, GRKN) through the completion of three sub-objectives: a. Identify sources of GRKN resistance in susceptible vegetable crops by screening representative core sets of PI lines from the USDA-GRIN germplasm collections of sweetpotato, pepper, watermelon, and cucumber. b. Develop high throughput root phenotyping tools and methodologies that can be used to assist and accelerate efforts to breed GRKN resistant vegetable cultivars. c. Map GRKN resistance genes and develop markers that can be used to accelerate the ingression of resistance into new resistant vegetable germplasm with favorable agronomic traits that can help manage this pest. d. Develop new GRKN resistant germplasm through controlled crosses.

Approach:
Cucumber, pepper, and sweetpotato germplasm will be screened in greenhouse to determine if there is host resistance for the newly emerging plant parasitic nematode, Meloidogyne enterolobii. Standard resistance assays for Fusarium wilt and crown rot and other diseases caused by Phytophthora capsici on various cucurbits will be performed. Selection, self-pollinations, and cross-pollinations will be performed to generate desired rootstocks for further testing. Seed increases will be performed as needed to supply cooperators with testable materials throughout the 4 year period. Field studies will be performed at the U.S. Vegetable Laboratory in Charleston, South Carolina, as well as at collaborating institutions in Florida and North Carolina. Grafting experiments will be performed in collaboration with with Clemson University. Molecular studies will be performed to quantify and qualify infection of pathogens, and determine resistance reactions. Polymerase chain reaction (PCR) based techniques will be used to verify resistant versus susceptible genotypes of plants.