Beet curly top resistance in USDA-ARS Ft. Collins Germplasm, 2011

Panella, Leonard W. and Strausbaugh, C.A. (2012) Beet curly top resistance in USDA-ARS Ft. Collins Germplasm, 2011. Plant Disease Management Reports. 6:p. FC084.

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Abstract

Twenty-two sugar beet (Beta vulgaris L.) lines from the USDA-ARS Ft. Collins sugar beet program were screened for resistance to Beet severe curly top virus (BSCTV) and other closely related Curtovirus species in 2011. Commercial cultivars Monohikari and HM PM90 were included as susceptible and resistant checks, respectively. The curly top evaluation was conducted at the USDA-ARS North Farm in Kimberly, ID which has Portneuf silt loam soil and had been in barley in 2010. The field was plowed both in the fall and the spring, fertilized (80 lb N and 120 lb P2O5/A) on 20 Apr 11, sprayed with Ethotron (2 pt/A), and roller harrowed. The germplasm was planted (density of 142,560 seeds/A) on 16 May. The plots consisted of two rows 10 ft long with 22-in row spacing, arranged in a randomized complete block design with three replications. The field was sprinkler irrigated and hand-weeded as necessary. Plant populations were thinned to about 47,500 plants/A on 19 Jun. Plants were inoculated at the four to six leaf growth stage on 27 Jun with approximately six viruliferous beet leafhoppers per plant. The leafhoppers had been reared in the greenhouse on viruliferous sugar beet plants. The beet leafhoppers were moved twice a day (right after sunrise and just before sunset) for 1 week by dragging a tarp through the field. The plants were sprayed with Lorsban 4E (1.5 pints/A) on 11 Jul to kill the beet leafhoppers. The plots were rated for foliar symptom development on 18 Jul using a scale of 0-9 (0 = healthy and 9 = dead; Mumford 1974), with disease index (DI) treated as a continuous variable. Data were analyzed using the general linear models procedure (Proc GLM-SAS), and Fisher’s protected least significant difference was used for mean comparisons. Yield data were not collected.
Curly Top development was uniform and no other disease problems were evident in the plot area. The test was evaluated while disease pressure was moderate and good symptom development occurred in the more susceptible lines. The experiment was rated only 3 weeks after inoculation, because of the severity of the epidemic; some of the more susceptible entries had died by 4 weeks and thus some of the differences among entries were no longer apparent. Only three experimental germplasms and the susceptible check were significantly different from the resistant controls. However, the three most resistant germplasm tested were not significantly different from the most resistant control (HM PM90, rated 3.1). All three also have increased tolerance of leaf spot caused by Cercospora beticola Sacc. (data not shown). The combination of resistance to both diseases gives this germplasm potential for use in development of hybrid parents in the Great Plains (Colorado, Wyoming, Western Nebraska, and Montana) because both of these diseases can severely limit yield. These lines also may be of use in the Red River Valley of North Dakota and Minnesota, as well as Michigan, two growing areas with severe leaf spot pressure.

Item Type:	Article
NWISRL Publication Number:	1456
Subjects:	Irrigated crops > Sugarbeet > Curly top Irrigated crops > Sugarbeet > Resistance Irrigated crops > Sugarbeet
Depositing User:	Users 6 not found.
Date Deposited:	10 May 2013 18:16
Last Modified:	04 Mar 2014 15:17
Item ID:	1492
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/1492