Evaluation of plant introduction lines of yellow squash (Cucurbita pepo) for resistance against single infection of Cucurbit chlorotic yellows virus (CCYV) and Cucurbit leaf crumple virus (CuLCrV)

Authors: ADELEKE, ISMAILA - University Of Georgia; KAVALAPPARA, SARITHA - University Of Georgia; CODOD, CLARENCE - University Of Georgia; KHAREL, PRASANNA - University Of Georgia; LUCKEW, ALEX - University Of Georgia; MCGREGOR, CECILIA - University Of Georgia; Simmons, Alvin; SRINIVASAN, RAJAGOPALBABU - University Of Georgia; BAG, SUDEEP - University Of Georgia

Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/26/2024
Publication Date: 6/4/2024
Citation: Adeleke, I.A., Kavalappara, S.R., Codod, C.B., Kharel, P., Luckew, A., Mcgregor, C., Simmons, A.M., Srinivasan, R., Bag, S. 2024. Evaluation of plant introduction lines of yellow squash (Cucurbita pepo) for resistance against single infection of Cucurbit chlorotic yellows virus (CCYV) and Cucurbit leaf crumple virus (CuLCrV). HortScience. 59(7):949-956. https://doi.org/10.21273/HORTSCI17861-24.
DOI: https://doi.org/10.21273/HORTSCI17861-24

Interpretive Summary: Whitefly-transmitted viruses are a major threat to cucurbit crops in the U.S. In the southeast U.S., cucurbit crops such as squash are mainly affected by cucurbit chlorotic yellows virus, cucurbit yellow stunting disorder virus, and cucurbit leaf crumple virus. Because mixed infections are common in the field, research was done to identify plants with resistance to single infections of whitefly-transmitted viruses. The amount of each virus was estimated and found to vary for two plant introduction (PI) squash lines (PI 171627 and PI 171625) compared with a susceptible line (Gentry); but, PI 171627 displayed the most resistance to the viruses. This information is useful for the agricultural community in the development of a management strategy for whitefly-transmitted viruses in squash fields.

Technical Abstract: Whitefly-transmitted viruses have emerged as a major threat to cucurbit production in the United States over the past several decades. In the southeast U.S., commercially produced cucurbits such as squash (Cucurbita pepo) are mainly affected by Cucurbit chlorotic yellows virus (CCYV), Cucurbit yellow stunting disorder virus (CYSDV), and Cucurbit leaf crumple virus (CuLCrV). Symptoms of these viruses include interveinal chlorosis, chlorotic spot, yellowing, and curling of the leaves depending on the virus. Assessment of individual viruses on the plant is nearly impossible because mixed infections are common in the field. To develop an effective management strategy, two plant introductions lines (PI 171625 and PI 171627) were screened in the greenhouse for resistance to a single infection of either CCYV or CuLCrV. Each line was compared with a susceptible commercial line (Gentry) in two independent trials. Virus load in each line was estimated at two different time points with RT-qPCR for CCYV and qPCR for CuLCrV. Disease severity and the area under the disease progress curve (AUDPC) were also estimated. PI 171627 was notable in displaying delayed appearance of symptoms, reduced virus load, and smaller AUDPC compared with PI 171625 and Gentry when infected with CCYV. However, there was no difference in the AUDPC for CuLCrV among the genotypes and commercial line.