Location: Northwest Irrigation and Soils ResearchTitle: Beet curly top resistance in USDA-ARS plant introduction lines, 2016 Author
Submitted to: Plant Disease Management Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/23/2017
Publication Date: 3/14/2017
Citation: Strausbaugh, C.A., Panella, L.W. 2017. Beet curly top resistance in USDA-ARS plant introduction lines, 2016. Plant Disease Management Reports. 11:V082. Interpretive Summary: Curly top in the semiarid production areas of the United States is caused by the Beet curly top virus (strains CA/Logan, CO, Kim1, Svr, and Wor) and vectored by the beet leafhopper. Resistant sugar beet cultivars became available in the 1930s prior to which curly top almost eliminated the sugar beet industry in the western United States. However, resistance is typically low to intermediate in commercial cultivars and has a tendency to be associated with lower yield potential. Thus, novel sources of resistance need to be identified and incorporated into commercial cultivars. Twenty-nine Plant Introduction Lines were screened for resistance to curly top. Three of the lines performed very well and have been incorporated into currently released germplasm. The results and germplasm will be accessible to interested parties through the USDA-ARS, NPGS GRIN database (http://www.ars-grin.gov/npgs/index.html).
Technical Abstract: Curly top caused by Beet curly top virus (BCTV) is a widespread disease problem vectored by the beet leafhopper in semiarid sugar beet production areas. Host resistance is the primary defense against this problem, but resistance in commercial cultivars is only low to intermediate. In order to identify novel sources of curly top resistance, twenty-nine Plant Introduction (PI) Lines were screened in a disease nursery in 2016. The lines were arranged in a randomized complete block design with four replications. A curly top epiphytotic was created by releasing approximately six viruliferous beet leafhoppers per plant at the four- to six-leaf growth stage on 20 Jun. Foliar symptoms were evaluated on 13 Jul using a scale of 0-9 (0 = healthy and 9 = dead) in a continuous manner. Curly top symptom development was uniform and no other disease problems were evident in the plot area. The disease pressure in the test was moderately severe with good symptom development in the susceptible check. Three of the PIs were not significantly different from the resistant checks based on the visual rating. These promising lines have been incorporated into the USDA-ARS sugar beet germplasm improvement program as potentially novel sources of resistance to BCTV.