Dalvir Dhadly, MS
Graduate Research Assistant
University of Georgia
Tifton, GA, USA
Saritha Kavalappara, PhD
Senior Research Associate - PL
University of Georgia
Tifton, Georgia, United States
Theodore McAvoy, PhD
Assistant Professor
University of Georgia, USA
Tifton, Georgia, United States
Paul Severns, PhD
Assistant Professor of Plant Disease Epidemiology
Department of Plant Pathology, University of Georgia
Athens, Georgia, United States
Alvin M. M. Simmons, PhD
ARS-Research Entomologist at USDA
United States Department of Agriculture (USDA), Charleston
Charleston, South Carolina, United States
Rajagopalbabu Srinivasan, PhD
Professor
University of Georgia
Griffin, GA, USA
Sudeep Bag, PhD
Associate Professor
University of Georgia
Tifton, GA, USA
The traditional understanding of begomovirus transmission only through the whitefly Bemisia tabaci has evolved with findings of seed transmission in some begomoviruses over the last decade. We investigated the seed transmissibility of cucurbit leaf crumple virus (CuLCrV), a bipartite begomovirus that has emerged as a significant constraint for yellow squash (Cucurbita pepo) production in the southeastern U.S. In the inoculated plants, we found high concentrations of CuLCrV in both male and female flower tissues, including pollen and ovules. The virus was also detected in fruit tissues, such as the endocarp and funiculus, which are adjacent to the seeds. CuLCrV was present in seeds, including the seed coat, endosperm, and embryo, which lack vascular connections. Virus presence was confirmed in the radicle, plumule, cotyledonary leaves, and true leaves of seedlings grown from infected seeds. In a grow-out test, CuLCrV infections were observed in 17 to 56% of progeny plants. To ensure that viral genome fragments were not mistaken for replicative forms, we used rolling circle amplification PCR, amplifying full-length DNA-A and DNA-B from seed tissues, seedlings, and a progeny plant. These findings confirm CuLCrV seed transmission under greenhouse conditions. Ongoing experiments are exploring the broader epidemiological significance of seed transmission in field settings. Grow-out assays using seeds collected from field-infected yellow squash fruits are underway, and investigations are also focused on the role of whiteflies in spreading the virus from infected progeny plants.