Quantitative trait locus analysis of fungal disease resistance factors on a molecular map of grapevine

Abstract

A full-sibling F1 population comprising 153 individuals from the cross of 'Regent' x 'Lemberger' was employed to construct a genetic map based on 429 molecular markers. The newly-bred red grapevine variety 'Regent' has multiple field-resistance to fungal diseases inherited as polygenic traits, while 'Lemberger' is a traditional fungus-susceptible cultivar. The progeny segregate quantitatively for resistances to Plasmopara viticola and Uncinula necator, fungal pathogens that threaten viticulture in temperate areas. A double pseudo-testcross strategy was employed to construct the two parental maps under high statistical stringency for linkage to obtain a robust marker frame for subsequent quantitative trait locus (QTL) analysis. In total, 185 amplified fragment length polymorphism, 137 random amplified polymorphic DNA, 85 single sequence repeat and 22 sequence characterized amplified region or cleaved amplified polymorphic sequence markers were mapped. The maps were aligned by co-dominant or doubly heterozygous dominant anchor markers. Twelve pairs of homologous linkage groups could be integrated into consensus linkage groups. Resistance phenotypes and segregating characteristics were scored as quantitative traits in three or four growing seasons. Interval mapping reproducibly localized genetic factors that correlated with fungal disease resistances to specific regions on three linkage groups of the maternal 'Regent' map. A QTL for resistance to Uncinula necator was identified on linkage group 16, and QTLs for endurance to Plasmopara viticola on linkage groups 9 and 10 of 'Regent'. Additional QTLs for the onset of berry ripening ("veraison"), berry size and axillary shoot growth were identified. Berry color segregated as a simple trait in this cross of two red varieties and was mapped as a morphological marker. Six markers derived from functional genes could be localized. This dissection of polygenic fungus disease resistance in grapevine allows the development of marker-assisted selection for breeding, the characterization of genetic resources and the isolation of the corresponding genes.

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

“…Rpv1/Run1 alleles were introduced in V. vinifera by backcrossing (Pauquet et al 2001). The locus Rpv3 was identified on chromosome 18 in the grape variety 'Regent' (Fischer et al 2004) and conferred significant resistance to downy mildew on both leaves and berries in all evaluated years ). In grapevine, this Rpv3 locus was responsible for causing the hypersensitive response (HR) at infection sites within two days after the inoculation (dpi) (Bellin et al 2009, Casagrande et al 2011).…”

Detection of downy and powdery mildew resistance QTL in a ‘Regent’ × ‘RedGlobe’ population

“…To date more than thirteen P. viticola major and minor resistance loci have been identified and mapped to chromosomes 4, 5, 7, 8, 9, 12, 14, 17 and 18 (Merdinoglu et al 2003;Fischer et al 2004;Welter et al 2007;Bellin et al 2009;Marguerit et al 2009;Zyprian et al 2009;Moreira et al 2011;Schwander et al 2012). Many of these loci were originally reported without specific gene names some of which were later assigned names in the catalogue of mapped resistance loci (http://www.vivc.de), leaving a few reported loci unnamed.…”

“…This region was also identified in an S1 population of M. rotundifolia 'Regale' (Blanc et al 2012). A cross between the resistant 'Regent' and susceptible 'Lemberger' yielded a resistance locus in the same region as Rpv2 (Fischer et al 2004;Welter et al 2007), but since 'Regent' does not have any M. rotundifolia ancestors (Eibach and Töpfer 2003) this locus is assumed to be different from Rpv2 and has therefore been designated Rpv3. Zyprian et al (2009) reported a major resistance locus on chromosome 18 of 'Villard Blanc', which was also detected in a Villard Blanc-derivative, 'Gf.Ga-52-42' (Schwander et al 2012).…”

“…This locus was inherited from V. amurensis. In the study by Fischer et al (2004) a minor resistance locus linked to VVMD27 on chromosome 5 was identified in three seasons. In contrast to Fisher et al (Fischer et al 2004), Welter et al (2007) detected this locus only in one season, highlighting the importance of quantitative trait loci (QTL) validation.…”

Breeding of fungal resistant varieties derived from Grüner Veltliner by chromosomal selection

“…Hence a specific task is to create an offspring of Grüner Veltliner that combines the estimated wine profile with some resistance genes derived from other Vitis species [5]. Seyval blanc, Villard blanc, or in our case, Malverina could function as resistance donors and they were applied as crossing partners [6]. These donor vines show satisfying stability in the field but still lack adequate wine quality.…”