Location: Vegetable Crops Research
Project Number: 5090-21220-007-040-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 11, 2025
End Date: Sep 10, 2028
Objective:
Research and development objectives will focus on investigations of inducible defenses in the cranberry plant. The primary objective of this work is to isolate existing cultivars, as well as novel crosses from ARS cranberry stock, that exhibit strong responses to methyl jasmonate (MeJA), a common plant-derived compound associated with plant defenses. Strength of induced responses to MeJA will be measured within the plant as well as among the insect pests feeding on/in the plant.
The sub-objectives are three-fold: 1) determine if induced defenses cause significant pest mortality; 2) determine if induced defenses operate via tissue toxicity, repellency, or both; 3) link strong defense phenotypes to gene sequences that will facilitate breeding of resistant cranberry cultivars.
The proposed work is critical because it will provide evidence of an intrinsic defense within the cranberry plant. Such inducible defenses can reduce pest damage, reduce grower costs, and ultimately reduce pesticide residues in cranberry fruit, thereby making cranberries a safer and more marketable crop globally.
Approach:
ooperator and ARS PIs will screen cranberry cultivars for their responses to methyl jasmonate (MeJA). Proof-of-concept data from ARS PIs indicate that select cranberry cultivars ('Pilgrim' germplasm) are extremely sensitive to MeJA treatments and thus represent a powerful means of reducing pest damage above- and below-ground.
MeJA-treated and untreated control plants will be exposed to feeding by insect pest species. Cooperator will examine patterns of insect feeding on cranberry plants, with a focus on below-ground pest feeding behaviors (on cranberry rhizomes and roots).
Based on feeding behaviors, pest mortality, and plant dynamics, candidates for genomic analyses will be isolated. Cranberry genomics will be conducted to link MeJA-induced defensive responses to plant phenotypes. Ultimately, cranberry plants with strong defensive responses will be used to breed new resistant cultivars.