Original Research ARTICLE
The Rpv3-3 haplotype and stilbenoid induction mediate downy mildew resistance in a grapevine inter-specific population.
- 1Research and Innovation Centre, Fondazione Edmund Mach, Italy
- 2Ethiopian Institute of Agricultural Research (EIAR), Ethiopia
- 3Department of Life Sciences, University of Trieste, Italy
- 4Research Centre of Viticulture and Oenology (CREA), Italy
The development of new resistant varieties to the oomycete Plasmopara viticola (Berk. & Curt) is a promising way to combat downy mildew (DM), one of the major disease threatening the cultivated grapevine (Vitis vinifera L.). Taking advantage of a segregating population derived from Merzling (a mid-resistant hybrid) and Teroldego (a susceptible landrace), 136 F1 individuals were characterized by combining genetic, phenotypic and gene expression data to elucidate the genetic bases of DM resistance and polyphenol biosynthesis upon P. viticola infection. An improved consensus linkage map was obtained by scoring 192 microsatellite markers. The progeny was screened for DM resistance and production of 42 polyphenols. QTL mapping showed that DM resistance is associated with the herein named Rpv3-3 specific haplotype and it identified 46 novel metabolic QTLs linked to 30 phenolics-related parameters. A list of the 95 most relevant candidate genes was generated by specifically exploring the stilbenoid-associated QTLs. Expression analysis of 11 genes in Rpv3-3+/- genotypes displaying disparity in DM resistance level and stilbenoid accumulation revealed significant new candidates for the genetic control of stilbenoid biosynthesis and oligomerization. These overall findings emphasized that DM resistance is likely mediated by the major Rpv3-3 haplotype and stilbenoid induction.
Keywords: candidate genes, disease symptom phenotyping, Merzling, Plasmopara viticola, Peroxidase, Polyphenols, QTL analysis, R-loci, Stilbenes, Vitis spp.
Received: 09 Nov 2018;
Accepted: 12 Feb 2019.
Edited by:Aziz Aziz, Université de Reims Champagne-Ardenne, France
Reviewed by:Courtney Coleman, University of Missouri, United States
Philippe JEANDET, Université de Reims Champagne-Ardenne, France
Copyright: © 2019 Malacarne, Vezzulli, Masuero, Vecchione, Chiara, Goremykin, Mehari, Banchi, Velasco, Stefanini, Vrhovsek, Zulini, Franceschi and Moser. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Giulia Malacarne, Fondazione Edmund Mach, Research and Innovation Centre, San Michele all'Adige, Italy, firstname.lastname@example.org