Cucurbit Leaf Crumple Virus (CuLCrV) is Seed Transmitted in Yellow Squash (Cucurbita pepo L.)

Authors: DHADLY, DALVIR - University Of Georgia; KAVALAPPARA, SARITHA - University Of Georgia; MCAVOY, THEODORE - University Of Georgia; SEVERNS, PAUL - University Of Georgia; Simmons, Alvin; SRINIVASAN, RAJAGOPALBABU - University Of Georgia; BAG, SUDEEP - University Of Georgia

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/13/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: It is well known that whiteflies transmit plant viruses to squash, and this is a problem in crop production. Also, several studies have demonstrated that several whitefly-transmitted plant viruses can also be seed-transmitted. A study was conducted to determine if the cucurbit leaf crumple virus can be seed-transmitted in yellow squash. Results from this study indicate that seeds from plants infected with the cucurbit leaf crumple virus contain this virus and transmit this virus to 15-56% of new plants when the seeds germinate and grow. This information is useful for helping the scientific and agricultural communities to better understand the development of cucurbit leaf crumple virus in yellow squash production.

Technical Abstract: The traditional understanding of begomovirus transmission exclusively through the whitefly Bemisia tabaci (Gennadius) has shifted 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 recently emerged as a severe constraint for yellow squash (Cucurbita pepo L.) production in the southeastern United States. We found high titers of CuLCrV in male and female flower tissues of infected squash, including pollen and ovules. The virus infiltrated the fruit tissues including endocarp and funiculus, which are anatomically positioned adjacent to the seeds. In seeds, CuLCrV was detected in the endosperm and embryo where there are no vascular connections, in addition to the seed coat. The virus was detected in the radicle, plumule, cotyledonary leaves, and true leaves of seedlings grown from seeds collected from infected fruits. In the grow-out test conducted, CuLCrV infections ranged from 17- 56% of the progeny plants. To ensure that partial viral genome fragments were not being mistaken for replicative forms of the virus, we performed RCA-PCR and amplified complete DNA-A an d DNA-B of CuLCrV from seed tissues, seedlings, and progeny plants of CuLCrV infected squash. We recovered the near complete DNA-A and DNA-B sequences of CuLCrV from a progeny plant, further validating our findings. Our results demonstrate that CuLCrV can move from vegetative to reproductive tissues of yellow squash, persist within the seeds, and subsequently induce infection in progeny plants, confirming its capacity for seed transmission.