Quantitative trait loci affecting pathogen resistance and ripening of grapevines

Abstract

Grapevines (Vitis vinifera L.) form the basis of viticulture, and are susceptible to diseases such as downy mildew (Plasmopara viticola) and powdery mildew (Erysiphe necator). Therefore, successful viticulture programs require the use of pesticides. Breeding for resistance is the only eco-friendly solution. Marker-assisted selection is currently widely used for grapevine breeding. Consequently, traits of interest must be tagged with molecular markers linked to quantitative trait loci (QTL). We herein present our findings regarding genetic mapping and QTL analysis of resistance to downy and powdery mildew diseases in the progenies of the GF.GA-47-42 ('Bacchus' × 'Seyval') × 'Villard blanc' cross. Simple sequence repeats and single nucleotide polymorphisms of 151 individuals were analyzed. A map consisting of 543 loci was screened for QTL analyses based on phenotypic variations observed in plants grown in the field or under controlled conditions. A major QTL for downy mildew resistance was detected on chromosome 18. For powdery mildew resistance, a QTL was identified on chromosome 15. This QTL was replaced by a novel QTL on chromosome 18 in 2003 (abnormally high temperatures) and 2004. Subsequently, both QTLs functioned together. Additionally, variations in the timing of the onset of veraison, which is a crucial step during grape ripening, were studied to identify genomic regions affecting this trait. A major QTL was detected on linkage group 16, which was supplemented by a minor QTL on linkage group 18. This study provides useful information regarding novel QTL-linked markers relevant for the breeding of disease-resistant grapevines adapted to current climatic conditions.

Behavior of grape breeding lines with distinct resistance alleles to downy mildew (Plasmopara viticola)

“…The effect of either Rpv1 or Rpv3 in single plants showed significantly higher resistance to downy mildew; however, genotypes with both resistance alleles showed no infection . In other studies, the combination of multiple resistance alleles, such as Rpv1 and Rpv3 (Calonnec et al 2013); Rpv3 is equal to QTLRgD as already described in Bellin et al (2009), Di Gaspero et al (2012, Zyprian et al (2016), Rpv3 and Rpv10 (Schwander et al 2012), Rpv3 and Rpv12 (Venuti et al 2013), likewise conferred significantly enhanced resistance to pathogen infection in comparison to single resistance alleles. Thus, the objective of this study was to develop, characterize, and select breeding lines homozygotic for the pyramided resistance alleles Rpv1 and Rpv3 for future breeding purposes.…”

“…Microsatellite markers Sc34_8 and Sc35_2 (NCBI STS database accession: GF111545 and GF111546), flanking the Rpv1 locus located on chromosome 12, and the markers GF18-06 (Schwander et al 2012) and GF18-08 (Zyprian et al 2016), located on chromosome 18, which flank the Rpv3 locus, were used to genotype the plants. The four pairs of primers were added in the same polymerase chain reaction (PCR) to obtain all amplicons at once.…”

The genetic background modulates the intensity of Rpv3‐dependent downy mildew resistance in grapevine

“…An analysis of multilocus haplotype frequencies with Rpv3 ‐linked markers has prefigured the existence of additional CWR alleles and their association with DM resistance in those lineages (Di Gaspero et al., ). One of these resistance haplotypes—conserved in the ‘Munson’ lineage—has been recently confirmed by QTL mapping (Zyprian et al., ).…”

“…During this process, the resistance haplotype, initially donated by an unknown North American species, has been transferred into the genetic background of cultivated varieties of V. vinifera , including European winegrapes, Caucasian winegrapes and table grapes from the Near East. In segregating populations, the resistance haplotype is necessary and sufficient to trigger a hypersensitive response (HR) in grapevine leaves infected by specific strains of P. viticola (Bellin et al., ; Zyprian et al., ). This resistance haplotype encodes NB‐LRR and LRR‐kinase receptors (Foria, ).…”

Development and Use of Biotechnology Tools for Grape Functional Analysis

“…The study of the genetic control of major agronomic traits in grapevine using QTL analysis allowed the elucidation of traits such as seedlessness and berry weight [12,18,[21][22][23]; berry phenolic composition [24][25][26][27][28]; aroma [29,30]; berry firmness [31,32]; fertility [9,33]; flower hermaphroditism [34]; cluster architecture [35]; pathogen resistance [34,[36][37][38]; plant phenology [39,40]; and adaptation to abiotic stresses [41] and to climate change [42]. Despite several of the reports allowed the identification of candidate sequences, just few of them have finally characterized the genes responsible for a particular function or trait.…”