Location: Vegetable Crops Research Unit
2013 Annual Report
Molecular mapping/cloning of downy mildew (DM) and zucchini yellow mosaic virus (ZYMV) resistances and understanding of molecular interactions between the downy mildew pathogen and cucumber host. For quantitative trait loci (QTL) mapping of DM resistance, we have developed several mapping populations including a RIL population from plant introduction line (PI) 197088 × Coolgreen and PI 197088 x Poinsett 76, as well as an F2:3 population from PI 330628 x 9930. Several F2 populations among old and new resistance sources are being developed for study of inheritance and allelism tests. For cloning of ZYMV resistance gene, SSR markers were scored across the genomic region carrying this resistance and linkage mapping was initiated. Crosses were also made between potyvirus resistant TMG1 cucumber with divergent susceptible cucumber germplasm for linkage mapping with SSRs across the genomic region carrying the zym locus. For DM-cucumber interactions, we compared infection stages and DM pathogen growth on susceptible and resistant cucumber lines. We also conducted transcriptome profiling in resistant and susceptible lines in response to DM pathogen inoculation.
Evaluate economic benefits. We have undertaken an extensive survey of slicing and pickling cucumber statistics through discussions with growers and processors. We have also developed an extensive discussion instrument for gathering information on regional value chains from grower to processor with the intent to understand relationships between growers and processors, the distribution of economic risks between growers and processors and quantitative values necessary to model the viable geographic scope of regional processing centers and the minimum feedstock necessary by size of processor.
Outreach. The research team members attended a number of stakeholders’ meetings or professional meetings, gave presentations and organized workshops aiming to enhance communication with various segments of the industry, and to educate the public on the need for sound scientific practices to resolve biological problems.
This research relates to objectives 1 and 2 through the development of applied genomics tools, molecular mapping/cloning of downy mildew and zucchini yellow mosaic virus resistances and understanding of molecular interactions between the downy mildew pathogen and cucumber host, evaluating economic benefits, and outreach.