Scientists at the USDA, ARS, U.S. Vegetable Laboratory in Charleston, SC evaluated the USDA, ARS citron watermelon germplasm collection for flowering time and fruit yield traits under field conditions over two years. They used a “genome-wide association study (GWAS)” to detect genomic regions and molecular (DNA) markers associated with flowering time and fruit yield traits. The new molecular markers will be useful in improving watermelon varieties for early flowering and maturity and yield performance via marker-assisted breeding.
Bazgha Zia is a postdoctoral researcher at the United States Vegetable Laboratory in Charleston, S.C. Bazgha’s research includes the development of virus resistant genetic material in cucurbits and identification of novel virus strains.
Scientists have constructed a comprehensive ‘super-pangenome’ for watermelon and its wild relatives, uncovering beneficial genes lost during domestication that could improve disease resistance and fruit quality of this vital fruit crop.
Citrullus amarus was screened for resistance to Pseudomonas leaf spot. Genetic markers associated with resistance to P. syringae and other diseases were identified. The results will facilitate breeding for resistance to PLS in watermelon.
Anju Biswas is a Post Doctoral fellow in the USDA-ARS-ORISE program at the U. S. Vegetable Laboratory at Charleston, SC. Her mentor is CucCAP Watermelon Team leader, Dr. Amnon Levi. The focus of her work is plant breeding, plant pathology, and genomics.
The CucCAP Watermelon team reported on project progress and ongoing research in April 2023.
The CucCAP watermelon team published 13 journal articles in 2022, 6 journal articles in 2021, and 15 journal articles in 2020.
Watermelon crops are increasingly threatened by infection by cucurbit downy mildew. While there are limited sources of disease resistance within cultivated watermelon, Citrullus amarus can be a valuable source of resistances. CucCAP scientists performed disease resistance screening and whole genome resequencing of 122 C. amarus accessions. Genome wide association analysis of these materials identified several marker-trait associations and candidate genes, providing potential resources for genomics-assisted breeding for resistance to CDM in watermelon.