Author
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Panella, Leonard |
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Strausbaugh, Carl |
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Submitted to: Plant Disease Management Reports
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 1/5/2011 Publication Date: 3/28/2011 Citation: Panella, L.W., Strausbaugh, C.A. 2011. Beet curly top resistance of USDA-ARS National Plant Germplasm System plant introductions, 2010. Plant Disease Management Reports. 5:FC066. Online publication doi:10.1094/PDMR05. Interpretive Summary: Twenty-six types of wild beet from the beet collection of the USDA-ARS National Plant Germplasm System were screened for resistance to Beet curly top in 2010. The curly top evaluation was conducted at the USDA-ARS North Farm in Kimberly, ID which had been in beans in 2009. The germplasm was planted on May 18. The plots were two rows 10 ft long with 22-in row spacing and arranged in a randomized complete block design with two replications. A breeding line from Betaseed, Inc., G6040, was included as a resistant check. The fields were sprinkler irrigated and hand weeded as necessary. Plant populations were thinned on June 19. Plants were inoculated at the four to six leaf growth stage on 23 Jun with six virus-carrying beet leafhoppers per plant. The plants were sprayed on July 7 to kill the beet leafhoppers. The plots were rated for leaf symptom development on July 15 using a scale of 1 to 9 (0 = healthy with no sign of disease and 9 = leaves brown and plant dead) and statistically analyzed. Curly top development was uniform and other disease problems were not evident in the plot area. The resistant check was not significantly more resistant than any of the 19 most resistant wild beets. The resistant wild beets had been collected in a number of European countries. Because of the narrow range of scores, it will be necessary to evaluate these germplasm once more at a future date. Technical Abstract: Twenty-six wild beet (Beta vulgaris subsp. maritima (L.) Arcang) accessions from the Beta collection of the USDA-ARS National Plant Germplasm System were screened for resistance to Beet severe curly top virus (BSCTV) and other closely related Curtovirus species in 2010. The curly top evaluation was conducted at the USDA-ARS North Farm in Kimberly, ID which had been in beans in 2009. The field was disked in the spring, fertilized on April 7, 2009, sprayed with Ethotron, and roller harrowed. The germplasm was planted on May 18. The plots were two rows 10 ft long with 22-in row spacing and arranged in a randomized complete block design with two replications. A breeding line from Betaseed, Inc., G6040, was included as a resistant check. The fields were sprinkler irrigated and hand weeded as necessary. Plant populations were thinned to about 47,500 plants/A on June 19. Plants were inoculated at the four to six leaf growth stage on June with six viruliferous beet leafhoppers per plant. The beet leafhoppers were moved twice a day (right after sunrise and just before sunset) for one week by dragging a tarp through the field. The plants were sprayed with Lorsban 4E on July 7 to kill the beet leafhoppers. The plots were rated for foliar symptom development on July 15 using a scale of 1 to 9 (0 = healthy with no sign of disease and 9 = leaves necrotic and plant dead), with disease index (DI) treated as a continuous variable. Data were analyzed using the general linear models procedure, and Fisher’s protected least significant difference was used for mean comparisons. Curly top development was uniform and other disease problems were not evident in the plot area. The PIs were a combination of annual and biennial plant types. The resistant check was not significantly more resistant than any of the 19 lowest rated lines (i.e. most resistant), which ranged from having a DI of 5.0 to having a DI of 6.0. The resistant germplasm were from a number of European countries. Because of the narrow range of scores (4.95 to 7.25), it will be necessary to evaluate these germplasm once more at a future date. |
