Identification of QTLs for resistance to powdery mildew and SSR markers diagnostic for powdery mildew resistance genes in melon (Cucumis melo L.)

• Published in: Theoretical and applied genetics Vol. 118; no. 1; pp. 165 - 175
• Main Authors: Fukino, Nobuko, Ohara, Takayoshi, Monforte, Antonio J, Sugiyama, Mitsuhiro, Sakata, Yoshiteru, Kunihisa, Miyuki, Matsumoto, Satoru
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Berlin/Heidelberg : Springer-Verlag 01.12.2008; Springer-Verlag; Springer; Springer Nature B.V
• Subjects: Agriculture; Ascomycota - pathogenicity; Biochemistry; Biological and medical sciences; Biomedical and Life Sciences; Biotechnology; Chromosome Mapping; Chromosomes, Plant; Classical genetics, quantitative genetics, hybrids; Cucumis melo - genetics; Cultivars; Disease; DNA, Plant - genetics; Fundamental and applied biological sciences. Psychology; Genetic Markers; Genetics of eukaryotes. Biological and molecular evolution; Immunity, Innate; Life Sciences; Minisatellite Repeats; Original Paper; Phenotype; Plant Biochemistry; Plant Breeding/Biotechnology; Plant Diseases - genetics; Plant Genetics and Genomics; Pteridophyta, spermatophyta; Quantitative Trait Loci; Vegetals; United States > US; Japan; Composite Interval Mapping; Linkage Group; Quantitative Trait Locus; Powdery Mildew; Melon; Agronomic character; Quantitative character; Cucurbitaceae; Identification; Marker; Fungus resistance; Gene; Dicotyledones; Angiospermae; Genetics; Spermatophyta; Agriculture; Cucumis melo
• ISSN: 0040-5752; 1432-2242
• DOI: 10.1007/s00122-008-0885-1

Powdery mildew caused by Podosphaera xanthii is an important foliar disease in melon. To find molecular markers for marker-assisted selection, we constructed a genetic linkage map of melon based on a population of 93 recombinant inbred lines derived from crosses between highly resistant AR 5 and susceptible 'Earl's Favourite (Harukei 3)'. The map spans 877 cM and consists of 167 markers, comprising 157 simple sequence repeats (SSRs), 7 sequence characterized amplified region/cleavage amplified polymorphic sequence markers and 3 phenotypic markers segregating into 20 linkage groups. Among them, 37 SSRs and 6 other markers were common to previous maps. Quantitative trait locus (QTL) analysis identified two loci for resistance to powdery mildew. The effects of these QTLs varied depending on strain and plant stage. The percentage of phenotypic variance explained for resistance to the pxA strain was similar between QTLs (R ² = 22-28%). For resistance to pxB strain, the QTL on linkage group (LG) XII was responsible for much more of the variance (41-46%) than that on LG IIA (12-13%). The QTL on LG IIA was located between two SSR markers. Using an independent population, we demonstrated the effectiveness of these markers. This is the first report of universal and effective markers linked to a gene for powdery mildew resistance in melon.