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Article|01 Apr 2022|OPEN
Candidate resistance genes to foliar phylloxera identified at Rdv3 of hybrid grape
Lu Yin1,2 , Avinash Karn3,4 , Lance Cadle-Davidson4,5 and Cheng Zou6 , Jason Londo4,5 , Qi Sun6 , Matthew D. Clark,1 ,
1Department of Horticultural Science, University of Minnesota, Twin Cities, Minnesota 55018, USA
2School of Life Science, Arizona State University, Tempe, Arizona 85281, USA
3AgReliant Genetics LLC, Lebanon, Indiana 46052, USA
4School of Integrative Plant Sciences, Cornell AgriTech, Cornell University, Geneva, New York 14456, USA
5Grape Genetics Research Unit, USDA-ARS, Geneva, New York 14456, USA
6Institute of Biotechnology, BRC Bioinformatics Facility, Cornell University, Ithaca, New York 14853, USA
*Corresponding author. E-mail: clark776@umn.edu

Horticulture Research 9,
Article number: uhac027 (2022)
doi: https://doi.org/10.1093/hr/uhac027
Views: 538

Received: 24 May 2021
Revised: 10 Apr 2022
Accepted: 04 Jan 2022
Published online: 01 Apr 2022

Abstract

The foliage of the native grape species Vitis riparia and certain cold-hardy hybrid grapes are particularly susceptible to the insect pest phylloxera, Daktulosphaira vitifoliae Fitch. A previous study using a cold-hardy hybrid grape biparental F1 population (N ~ 125) detected the first quantitative trait locus (QTL) for foliar resistance on chromosome 14, designated as resistance to Daktulosphaira vitifoliae 3 (Rdv3). This locus spans a ~ 7-Mbp (10–20 cM) region and is too wide for effective marker-assisted selection or identification of candidate genes. Therefore, we fine mapped the QTL using a larger F1 population, GE1783 (N ~ 1023), and genome-wide rhAmpSeq haplotype markers. Through three selective phenotyping experiments replicated in the greenhouse, we screened 184 potential recombinants of GE1783 using a 0 to 7 severity rating scale among other phylloxera severity traits. A 500-kb fine mapped region at 4.8 Mbp on chromosome 14 was identified. The tightly linked rhAmpSeq marker 14_4 805 213 and flanking markers can be used for future marker-assisted breeding. This region contains 36 candidate genes with predicted functions in disease resistance (R genes and Bonzai genes) and gall formation (bifunctional 3-dehydroquinate dehydratase/shikimate dehydrogenase). Disease resistance genes suggest a traditional R-gene-mediated resistance mechanism often accompanied by a hypersensitive response, which has been widely studied in the plant pathology field. A novel resistance mechanism, non-responsiveness to phylloxera gall formation is proposed as a function of the bifunctional dehydratase gene, which plays a role in gallic acid biosynthesis and is important in gall formation. This study has implications for improvement of foliar phylloxera resistance in cold-hardy hybrid germplasm and is a starting place to understand the mechanism of resistance in crops to gall-forming insects.