Location: Vegetable Crops Research
Project Number: 5090-21000-062-24-T
Project Type: Trust Fund Cooperative Agreement
Start Date: Oct 1, 2012
End Date: Jul 31, 2016
1) Develop a SNP-based high-resolution genetic map through genotyping by sequencing in a recombinant inbred line population; 2) Develop an integrated, high-resolution genetic-physical map with SSR and SNP markers in cucumber; 3) Conduct QTL mapping of different sources of resistance against the new downy mildew strain and powdery mildew.
1) Development of SNP- and SSR-based high-resolution genetic map: a. Develop a mapping population with 175 RILs from Gy14 × 9930 mating b. SNP genotyping of this population by re-sequencing c. Develop a SNP- and SSR-based high-resolution linkage map with this population d. Anchoring cucumber draft genome scaffolds onto this genetic map to develop an improved chromosome-level genome assembly; 2) QTL mapping of downy mildew and powdery mildew resistances: a. Resistance sources: PI 197088, PI 330628, Gy14 (dm-1) b. Mapping populations: F2 and F2:3 from different crosses c. Phenotyping: greenhouse artificial inoculation, and field trials (both ARS and sponsor) d. Genotyping: SSRs, indels, SNP-based CAP, dCAPS e. Fine mapping of major QTL for downy mildew and powdery mildew resistances, and clarify the linkage relationships of major QTLs for the two resistance genes.