Location: Vegetable Research
Project Number: 6080-22000-032-006-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Oct 1, 2019
End Date: Aug 31, 2023
Objective:
1. Identify resistant germplasm from the USDA collections of Citrullus amarus (Watermelon) and Cucurbita pepo (Squash) against the different species of the phytopathogenic bacterium Pseudomonas.
2. Develop F1, F2 and F3 populations of the resistant individuals crossed to a susceptible line for use in quantitative trait loci (QTL) analysis.
3. Identify QTL associated with resistance and develop Kompetitive allel-specific Polymerase chain reaction (KASP) markers for use in marker assisted breeding programs.
Approach:
1) Use biological assays to screen the Citrullus (C.) amarus collection (133 PI accessions) and the recently developed core collection of Cucurbita pepo. 2) The ARS laboratory has recently re-sequenced the entire collection of C. amarus, and in addition, the CucCAP Specialty Crops Research Initiative collaborators have performed Genotype by Sequencing of the C. pepo core collection (384 PI). The data will be used for initial identification of quantitative trait loci (QTL) by way of Genome-Wide Association Studies (GWAS). 3) QTL identified will then be further narrowed using a combination of QTLseq and standard QTL analysis. 4) The narrowed QTL region(s) will then be use to develop Kompetitive allel-specific Polymerase chain reaction (KASP) markers that will be validated and published for use in marker assisted selection breeding programs world-wide.
