Induced resistance against bacterial wilt of annual bluegrass (Poa annua L.) caused by Xanthomonas translucens pv. poae
Bacterial wilt of annual bluegrass (Poa annua L.) is caused by the gram negative bacterium Xanthomonas translucens pv. poae. Poa annua and the disease bacterial wilt are commonly found on golf course greens throughout the United States. There are currently few options to control bacterial wilt of Poa annua. Application of certain chemicals can induce resistance against plant pathogens by triggering components of defense related pathways, such as systemic acquired resistance and induced systemic resistance, which prime defense responses. The goal of this project is to test whether treatments that prime the expression of plant defenses are able to control bacterial wilt in Poa annua. ^ Fifteen isolates of Xanthomonas translucens pv. poae were isolated from diseased turf samples sent into the University of Rhode Island Turf Diagnostic Lab. The isolates were tested for virulence on Poa annua. Two levels of virulence were observed; highly virulent isolates that caused 95 to 100% plant mortality, and less virulent isolates that caused 10 to 50% plant mortality. Plant age, average tiller number, and the number of bacteria used for inoculation were tested for their effect on the ability of Actigard to control bacterial wilt of Poa annua. All three factors were found to influence the ability of Actigard to induce resistance against bacterial wilt. ^ Certain chemical and microbial treatments are able to control plant diseases by priming the expression of plant defenses. Treatments that prime for induced resistance against other plant pathogens in other in other host plants were tested for their ability to prime for resistance against bacterial wilt of Poa annua. Actigard was the most effective treatment, followed by 2,6-dichloroisonicotinic acid. Other treatments that gave some control included saccharin, beta-amino butyric acid, and trehalose. Salicylic acid, Aliette, Civitas, imidicloprid, Insignia, potassium silicate were also tested, and did not cause any reduction in disease severity.^
Agriculture, Plant Pathology
Arielle M Chaves,
"Induced resistance against bacterial wilt of annual bluegrass (Poa annua L.) caused by Xanthomonas translucens pv. poae"
Dissertations and Master's Theses (Campus Access).