Development of a field inoculation method to screen for sugar beet seedling resistance to Fusarium oxysporum f. sp. beta.

Authors: Panella, Leonard; Vagher, Travis; FENWICK, ANN - Beet Sugar Development Foundation; Hanson, Linda

Submitted to: Journal of Sugar Beet Research
Publication Type: Abstract Only
Publication Acceptance Date: 1/15/2015
Publication Date: 7/15/2015
Citation: Panella, L.W., Vagher, T.O., Fenwick, A., Hanson, L.E. 2015. Development of a field inoculation method to screen for sugar beet seedling resistance to Fusarium oxysporum f. sp. beta. Journal of Sugar Beet Research. 52 (1&2):104-105.

Interpretive Summary: Fusarium yellows is an important disease in many sugarbeet production area in the U.S. and yield losses can be devastating. Also seedling damping off caused by Fusarium can result in serious damage to the sugarbeet stand establishment. This can lead to a severe loss in yield. The objective of this research has been to develop the methodology for field screening of sugarbeet for Fusarium resistance at the seedling stage. Fusarium isolate, FOB220a (highly virulent), was used to prepare infested barley. Sterile barley inoculated with a liquid culture was incubated at room temperature until all barley grains were fully colonized. Ground, dried inoculum, added to the seed packets, was used to inoculate field experiments. Sterile barley was used as a control. The nursery consisted of one-row plots (75 cm spacing), 4 m long, at the ARS Research Farm, in Fort Collins, CO. Trials were planted in 2008 and 2010 using four public germplasms, which varied in their resistance to FOB220a – FC708, FC716, FC709-2, and FC702-2. In both years, seedling stands were counted every 7-10 days for six weeks post emergence. A final count was made 16 weeks post emergence in 2008. In 2008, there were significant differences between the inoculated and control plots, when averaged over the four lines and the four dates of seedling counts. When looking at each week, there were significant differences in all weeks except for the first seedling count ten days after planting. In 2010 there were significant differences among the four germplasms and the four evaluation dates. All of the inoculated lines lost seedlings over time, even though 3 of the 4 lines started within 10% of the control at the first counting date. There were clear differences between the lines at the last evaluation date.

Technical Abstract: Fusarium yellows is an important disease in many sugarbeet production area in the U.S. and yield losses can be devastating. Also seedling damping off caused by Fusarium can result in serious damage to the sugarbeet stand establishment. This can lead to a severe loss in yield. The objective of this research has been to develop the methodology for field screening of sugarbeet for Fusarium resistance at the seedling stage. Fusarium oxysporum f. sp. betae isolate, FOB220a (highly virulent), was used to prepare infested barley inoculum. Sterile barley inoculated with a liquid culture was incubated at room temperature until all barley grains were fully colonized. Ground, dried inoculum, added to the seed packets, was used to inoculate field experiments. Sterile barley was used as a control. The nursery consisted of one-row plots (75 cm spacing), 4 m long, at the ARS Research Farm, in Fort Collins, CO. Trials were planted in 2008 and 2010 using four public germplasms, which varied in their resistance to FOB220a – FC708, FC716, FC709-2, and FC702-2. In both years, seedling stands were counted every 7-10 days for six weeks post emergence. A final count was made 16 weeks post emergence in 2008. In 2008, there were significant differences between the inoculated and control plots, when averaged over the four lines and the four dates of seedling counts. When looking at each week, there were significant differences in all weeks except for the first seedling count ten days after planting. In 2010 there were significant differences among the four germplasms and the four evaluation dates. All of the inoculated lines lost seedlings over time, even though 3 of the 4 lines started within 10% of the control at the first counting date. There were clear differences between the lines at the last evaluation date.