Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 7/28/2005
Publication Date: 8/5/2005
Citation: Glenn, D.L., Peterson, G.L. 2005. Effect of sodium phosphate salts and pH on teliospore germination and basidiospore production of Tilletia indica [abstract]. Phytopathology. 95:535.
Technical Abstract: Teliospores of Tilletia indica germinate on the soil surface to produce basidiospores that can infect flowering wheat heads under favorable conditions. Reducing teliospore germination during the infection window may lower incidence of Karnal bunt. In laboratory assays, sodium phosphate inhibited spore germination and basidiospore production. Water agar plates were amended with monobasic or dibasic sodium phosphate (10mM) at pH 4.8, 6, 7, and 8.4. Teliospores plated on the unamended medium germinated at comparable rates across the respective pH range (47, 48, 44, 43%). Germination was reduced at all pH levels in the presence of monobasic or dibasic sodium phosphate, with the highest reduction at pH 7. At pH 7, monobasic and dibasic sodium phosphate reduced germination by 73 and 93%, respectively. In a separate study, germination rates were comparable among unamended plates (48%) and plates amended with the salts sodium chloride (50%) or potassium chloride (41%) at 20 mM, suggesting the phosphate anion and not the base cation is responsible for inhibition. The effect of sodium phosphate on spore germination on the soil surface is currently under study. Timely applications of a phosphate compound to infested field soils may inhibit or delay teliospore germination during the wheat infection window and thereby reduce disease incidence.