Arthropod-Plant Interactions (2020) 14, 57-65

Malcolm Macaulay, Luke Ramsay and Inger Åhman (2020)
Quantitative trait locus for resistance to the aphid Rhopalosiphum padi L. in barley (Hordeum vulgare L.) is not linked with a genomic region for gramine concentration
Arthropod-Plant Interactions 14 (1), 57-65
Abstract: Gramine is an indole alkaloid found in certain grass species. Results of previous studies have diverged as to whether this compound might cause resistance to aphids or not. In a breeding program aiming to introduce resistance to the cereal pest Rhopalosiphum padi L. in barley, a cultivar has been crossed with the progenitor of cultivated barley, Hordeum vulgare ssp. spontaneum, and an F₁-derived population of doubled haploid (DH) lines was screened both for seedling gramine concentration and resistance to R. padi. The resistance was measured as individual aphid growth in the laboratory. The present study aims to determine if there is a genetic relationship between aphid growth retardation and gramine concentration. To do so, the lines were genotyped with a 384 SNP oligonucleotide pool assay and QTL analyses were performed for both traits. A previously identified aphid resistance locus on the distal part of chromosome 2HS was thereby confirmed, with resistance inherited from H. v. ssp. spontaneum, whereas one or more QTL for gramine concentration were potentially indicated on chromosome 3H, thus corroborating that the two traits are not linked genetically.
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Database assignments for author(s): Inger Åhman

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Rhopalosiphum padi	Barley (Hordeum vulgare)