Location: Northwest Irrigation and Soils Research
Title: Beet curly top resistance in USDA-ARS plant introductions, 2013 Authors
Submitted to: Plant Disease Management Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 27, 2014
Publication Date: March 29, 2014
Citation: Strausbaugh, C.A., Panella, L.W. 2014. Beet curly top resistance in USDA-ARS plant introductions, 2013. Plant Disease Management Reports. 8:FC171. Interpretive Summary: Curly top in the semiarid production areas of the United States is caused by one of three Curtovirus species (BCTV, BMCTV, and BSCTV) 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. Thirty Plant Introduction Lines were screened for resistance to curly top. Three of the lines performed very well and will be investigated further. If novel sources of resistance are confirmed in the lines, the resistance will be incorporated into germplasm lines and released to the general public.
Technical Abstract: Curly top caused by Curtovirus species 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, thirty Plant Introduction (PI) Lines were screened in a disease nursery in 2013. The lines were arranged in a randomized complete block design with three replications. A curly top epiphytotic was created by releasing approximately 6 viruliferous beet leafhoppers per plant at the four- to six-leaf growth stage on 27 Jun. Foliar symptoms were evaluated on 16 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. Twelve of the PIs were not significantly different from the resistant control, HM PM90. Of these 12 PIs, three performed extremely well, one from Greece (PI546423) and two from Portugal (PI604524, PI604539). They will be retested and, if resistance is confirmed, they will be incorporated into the USDA-ARS germplasm improvement program as potentially novel sources of resistance to BSCTV and closely related Curtovirus species.