Location: Vegetable Research
Project Number: 6080-21000-020-050-T
Project Type: Trust Fund Cooperative Agreement
Start Date: Dec 1, 2025
End Date: Nov 30, 2028
Objective:
This BARD proposal is based on a current proposal aimed to enhance watermelon cultivars for drought tolerance. The main objective of the proposed research is to utilize the genetic diversity that exists in the USDA watermelon germplasm and genetic populations to enhance drought tolerance in watermelon cultivars. To identify gene loci and develop molecular markers associated with drought tolerance in watermelon. Develop advanced lines useful for incorporating gene loci conferring drought tolerance into the genome of elite watermelon cultivars.
Approach:
Upon completion of evaluating germplasm collections and genetic populations derived from a cross of the desert watermelon (Citrullus colocynthis) or citron watermelon (Citrullus amarus) with watermelon cultivars we will develop and validate molecular markers that will be used to incorporate gene conferring desirable root traits into the genome of watermelon cultivars. In addition, a recombinant inbred line (RIL) population will be used in a 'genomic selection' study. Selected superior lines will be evaluated at the Central Valley, California (in collaboration with the extension team at University of California. The genetic populations will be extensively phenotyped for drought tolerance and fruit quality traits and genotyped (genome sequencing). The data generated in this study will then be used in 'genomic selection' approach to incorporate the drought tolerance trait into watermelon cultivars. Machine learning models will be built for the training population to generate marker effects and genome-wide estimated breeding values (GEBVs). A set of idiotypes with drought tolerance and desirable fruit quality traits will be selected and used in the development of a testing population, and in further development of drought tolerant watermelon lines with sufficient fruit qualities.