Location: Vegetable Research
Project Number: 6080-22000-028-019-N
Project Type: Non-Funded Cooperative Agreement
Start Date: Apr 1, 2015
End Date: Mar 31, 2020
Objective:
1. Evaluate watermelon germplasm core collections from USDA and China for resistance to cucumber green mottle mosaic virus (CGMMV).
2. Develop breeding populations and determine the genetic inheritance of resistance to CGMMV in watermelon.
3. Use genotyping-by-sequencing to identify SNPs linked to the CGMMV resistance trait for marker-assisted selection.
Approach:
1. Arrangement to transfer 250 accessions of USDA core watermelon collections will be coordinated by USVL and shipped to Cooperator scientist.
2. Evaluate 250 plant introductions in the USDA watermelon core collection and 200 Chinese watermelon germplasm lines at ZAAS in Hanzhou, China, for resistance to cucumber green mottle mosaic virus (CGMMV) with technical advice from ARS scientists.
3. Select and develop selected lines with resistance to CGMMV. The most resistant lines will be contained in a greenhouse and self-pollinate the most resistant progenies in advanced selection to develop homozygous S4 resistant lines.
4. The S4 resistant lines will be used to develop genetic populations (F1, F2, and BC1) segregating for CGMMV resistance. These genetic populations will be transferred to USVL and used in genetic studies to determine the inheritance of resistance in watermelon.
5. Leaf tissue samples from those phenotypically well-characterized population will be collected, DNA extracted and used for genotyping-by-sequencing.
6. Data analysis will be conducted at USVL and those SNP markers associated the CGMMV resistance locus (loci) will be identified and used for marker assisted selection.
