|ELLIS, MARGARET - California State University|
|DIAZ, JOSUE - California State University|
|HUTMACHER, ROBERT - University Of California, Davis|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2019
Publication Date: 8/5/2016
Citation: Ellis, M.L., Diaz, J., Hutmacher, R., Ulloa, M. 2016. Disease development in cotton when co-inoculated with the soilborne fungi fusarium oxysporum f. sp. vasinfectum race 4 and rhizoctonia solani. Meeting Abstract. 252-P1.
Technical Abstract: Fusarium oxysporum f. sp. vasinfectum (FOV) race 4 is a virulent wilt pathogen of cotton, that can also cause seedling damping-off when high levels of inoculum are present in the field. Another important seedling disease of cotton is caused by Rhizoctonia solani. Previous speculations have suggested there is an increase in wilt symptoms caused by FOV race 4 when R. solani is present in the same field. Therefore, the goal of this study was to evaluate the possible interactions between FOV race 4 and R. solani in a co-inoculation assay. Planting material included one FOV race 4 susceptible line and four FOV race 4 resistant lines. Oat-infested inoculum, was prepared using the FOV race 4 isolate TM-13 and R. solani isolate R1. The infested oats were mixed with potting soil at a ratio of 1 part fungal inoculum to 3 parts potting soil. Three seeds were then planted into the infested soil. The experiment was a randomized complete block design, with four replications as the blocking factor. The experiment was conducted three times. After five weeks, data for stand count, plant height, foliar and vascular symptoms were recorded. For all data collected there was a significant difference among fungal treatment (P<0.0001). There was no difference between varieties. Our results suggest an interaction between these two pathogens. Infection by R. solani may compromise the plants ability to compensate for FOV race 4 stresses thereby increasing FOV race 4 symptoms in the field.