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ARS Home » Midwest Area » Madison, Wisconsin » Vegetable Crops Research » Research » Publications at this Location » Publication #347511

Research Project: Genetic Enhancement of Allium, Cucumis, and Daucus Germplasm

Location: Vegetable Crops Research

Title: Precision phenotyping of epicuticular waxes associated with insect resistance

Author
item Munaiz, Eduardo - University Of Wisconsin
item Havey, Michael

Submitted to: Plant and Animal Genome
Publication Type: Abstract Only
Publication Acceptance Date: 1/5/2018
Publication Date: 1/13/2018
Citation: Munaiz, E., Havey, M.J. 2018. Precision phenotyping of epicuticular waxes associated with insect resistance [abstract]. Plant and Animal Genome XXVI Proceedings. Paper No. P0135.

Interpretive Summary:

Technical Abstract: Accurate phenotyping is imperative for linkage mapping and association genetics. Amounts and types of epicuticular waxes on the leaf surface are important for plant-insect interactions. In onion, specific wax profiles are associated with resistance to the insect pest Thrips tabaci. Epicuticular wax profiles are determined using Gas Chromatography Mass Spectrometry (GCMS), and affected by genetic and environmental factors. To unravel environmental effects and best phenotyping approaches, we studied 15 onion accessions with a wide range of wax composition, including three double haploids (DHs) with copious amounts of waxes and a mutant line (“glossy”) with low amounts of waxes. Accessions were evaluated for amounts and types of epicuticular waxes under greenhouse (GH) and field conditions. GCMS revealed that the ketone hentriocontanone-16 (H16) is the most prevalent wax on onion leaves. There was significant variation for H16 among accessions, and it was significantly higher on the waxy DHs and lowest on the mutant line. Amounts of H16 varied significantly across environments, even though relative quantities were consistent within environments. Although genotype by environment (GxE) interactions were not significant, GH conditions allowed for greater power of discrimination among accessions. This study supports biochemical analyses of epicuticular waxes for phenotyping and selection of plants for modified profiles associated with insect resistance.