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ARS Home » Pacific West Area » Davis, California » Crops Pathology and Genetics Research » Research » Research Project #437655

Research Project: Development of RNA Interference-Based Resistance in Almond and Walnut Rootstocks Against Phytophthora Pathogens

Location: Crops Pathology and Genetics Research

Project Number: 2032-22000-016-069-A
Project Type: Cooperative Agreement

Start Date: Nov 1, 2019
End Date: Mar 31, 2022

Objective:
1) Evaluation of walnut transgenic lines for Phytophthora resistance in the greenhouse. 2) Development of a transformation system for almond rootstocks.

Approach:
1) A part of conserved protein coding genes in Phytophthora have been integrated in the genomes of walnut rootstocks, and shoots of transformant plants are available. Shoots in the vitro seedlings will be inoculated with a Phytophthora pathogen and walnut transformant lines that show increased resistance (small or no necrotic lesions) will be propagated, regenerated to whole plants in pots, and then inoculated again. Three months after inoculation, resistance to the pathogens will be assessed according to severity of crown and root rot. 2) We have developed somatic embryos of almond x peachhybrids. The Agrobacterium-based walnut transformation system will be used to transform the almond x peach hybrid somatic embryos with gene fragments that are effective in suppression of Phytophthora.