Monitoring the distribution, incidence, and symptom expression associated with cotton leafroll dwarf virus in the southern United States using a sentinel plot system

Authors: KOEBERNICK, J - Auburn University; HAGAN, A - Auburn University; ZACCARON, M - Auburn University; ESCALANTE, C - Auburn University; JACOBSON, A - Auburn University; BOWEN, K - Auburn University; STRAYER-SCHERER, A - Auburn University; HEILSNIS, B - Auburn University; BROWN, S - Auburn University; SIKORA, E - Auburn University; ALLEN, T - Mississippi State University; FASKE, T - University Of Florida; BOURLAND, F - University Of Arkansas; GREENE, J - Clemson University; HUSETH, A - North Carolina State University; KELLY, H - University Of Tennessee; KEMERAIT, R - University Of Georgia; KERNS, D - Texas A&M University; MULVANEY, M - University Of Florida; PRICE, P - Louisana State University; SMALL, I - University Of Florida; TAYLOR, S - Virginia Tech; WANG, H - Clemson University; CONNER, K - Auburn University

Submitted to: PhytoFrontiers
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/4/2024
Publication Date: 8/30/2024
Citation: Koebernick, J.C., Hagan, A.K., Zaccaron, M., Escalante, C., Jacobson, A.L., Bowen, K.L., Strayer-Scherer, A., Heilsnis, B., Brown, S., Sikora, E.J., Allen, T.W., Faske, T.R., Bourland, F., Greene, J.K., Huseth, A., Kelly, H., Kemerait, R.C., Kerns, D., Mulvaney, M., Price, P.P., Small, I., Taylor, S., Wang, H., Conner, K. 2024. Monitoring the distribution, incidence, and symptom expression associated with cotton leafroll dwarf virus in the southern United States using a sentinel plot system. PhytoFrontiers. 4(4):671–681. https://doi.org/10.1094/PHYTOFR-02-24-0008-R.
DOI: https://doi.org/10.1094/PHYTOFR-02-24-0008-R

Interpretive Summary: Cotton leafrolll dwarf virus (CLRDV) is considered a devastating pathogen in the cotton industry. It can cause severe yield losses depending on the region and type of strain. In the United States, CLRDV was first reported in Alabama in 2017; therefore, scientists and extension specialists from different universities united to conduct a survey to detect and characterize the geographical localization of CLRDV across several states in the cotton belt of the United States. This study represented the first multi-state report of CLRDV monitoring across the Cotton Belt. The multi-state effort consisted of setting up cotton plots to collect leaf samples that were analyzed for CLRDV at the Auburn University Plant Diagnostics Lab in Alabama. During sample collection, symptoms associated with the infection of CLRDV were also recorded. Results indicated that CLRDV was prevalent across the southern United States. This information will benefit the cotton industry as efforts to develop management strategies continue that will mitigate future outbreaks of severe strains of CLRDV.

Technical Abstract: Cotton leafroll dwarf virus (CLRDV), transmitted by the cotton aphid (Aphis gossypii), was first confirmed in upland cotton (Gossypium hirsutum L.) in Alabama, United States in 2017. Following the initial confirmation of CLRDV, subsequent observations of symptomatic plants followed by confirmation via rPCR were made in neighboring states in 2018. To assess the distribution and incidence of CLRDV, and incidence of presumed symptoms across the southern cotton belt, a multidisciplinary team established sentinel plot survey sites at 16 experiment stations in 11 states stretching from Texas in the west to Virginia in the east and as far north as Tennessee and south as Florida beginning in 2019. Field trials were conducted over a three-year period using multiple cotton cultivars that were adjusted annually. Cotton plots were evaluated by a single evaluator to attempt to correlate symptom incidence across the cotton growing region with virus incidence in cotton plant tissues using reverse transcriptase PCR. Percent symptom incidence, based on expression from within plots at each location, differed across the region and ranged from a low of 0% to a high of 75% with a low average from all locations of 11.4% in 2021 to an average high of 28.0% in 2020. Though symptom incidence suggested the presence of CLRDV, there were instances where symptoms were observed but virus presence was not confirmed by PCR. CLRDV was confirmed from all locations regardless of year, which suggests that it has become endemic throughout the eastern range of the United States cotton production area.