A standardised method for the quantitative analysis of resistance to grapevine powdery mildew

• Published in: European journal of plant pathology Vol. 133; no. 2; pp. 483 - 495
• Main Authors: Miclot, Anne-Sophie, Wiedemann-Merdinoglu, Sabine, Duchêne, Eric, Merdinoglu, Didier, Mestre, Pere
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.06.2012; Springer; Springer Nature B.V; Springer Verlag
• Subjects: Agriculture; Airborne microorganisms; Biological and medical sciences; Biomedical and Life Sciences; breeding; Cell counters; counters; Crop diseases; Cultivars; disease control; drying; Ecology; Environmental degradation; Erysiphe necator; Fruits; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; Fungi; Fungicides; Gene mapping; Genetic analysis; genetic techniques and protocols; Infection; Inoculation; inoculation methods; Life Sciences; loci; Pathogens; Phytopathology. Animal pests. Plant and forest protection; Plant breeding; Plant Pathology; Plant resistance; Plant Sciences; powdery mildew; Production costs; quantitative analysis; Quantitative trait loci; Selective breeding; Sporulation; Uncinula necator; Vegetal Biology; Vitaceae; Vitis vinifera; Disease resistance; .; Grapevine breeding; Ascomycota; Plant pathogen; Erysiphe necator; Method; Vitis vinifera; Fungi; Resistance; Fruit crop; Vitidaceae; Dicotyledones; Angiospermae; Uncinula necator; Spermatophyta; Quantitative analysis
• ISSN: 0929-1873; 1573-8469
• DOI: 10.1007/s10658-011-9922-z

Powdery mildew caused by Erysiphe necator is one of the most important diseases affecting grapevine ( Vitis vinifera , L.). Control of this pathogen is based on the use of fungicides, which cause environmental damage and increase production costs. A cost-effective and environmentally friendly alternative to control the disease relies on using resistant varieties. While most V. vinifera cultivars are susceptible to powdery mildew, several species belonging to the Vitaceae have been described as resistant. Several loci for resistance to grapevine powdery mildew have been identified through genetic analysis of segregating populations derived from different resistance sources. Identifying quantitative trait loci (QTL) with minor effects on the resistance may prove valuable in a strategy of pyramiding, which aims at increasing the durability of the resistance. However, current methods for evaluation of resistance either do not take into account quantitative variations, or, if they do, are not adapted to large sample sets. Here we develop a method for the analysis of quantitative resistance to grapevine powdery mildew in large populations. We devised a semi-quantitative resistance scale and confirmed the usefulness of a cell counter to quantify sporulation. We compared three inoculation methods and identified dry inoculation using a settling tower as the one giving the best infection. Finally, we confirmed the value of the method by applying it to a set of plants segregating for resistance to E. necator . Using the method described here for the quantitative analysis of the resistance to powdery mildew will prove valuable for breeding for durable resistance.