ARS | Publication request: EFFECTS OF MEDIA AND PH ON UREDINIOSPORE GERMINATION AND GERM-TUBE ELONGATION OF PUCCINIA HEMEROCALLIDIS

Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: May 1, 2005
Publication Date: June 1, 2005
Citation: Li, Y.H., Windham, M.T., Trigiano, R.N., Fare, D.C., Spiers, J.M., Copes, W.E. 2005. Effects of media and ph on urediniospore germination and germ-tube elongation of puccinia hemerocallidis. American Phytopathological Society Annual Meeting 95:S60.

Technical Abstract: Effects of a PDA and five gelling agents (Gelrite, Agarose, Phytagar, Agar No. 3 and Bacto-agar) at five concentrations (0.5, 1, 2, 4 and 6%) on urediniospore germination of Puccinia hemerocallidis, the causal agent of daylily rust, were examined. Media and concentrations significantly affected urediniospore germination, which was measured after six hours. Urediniospores did not germinated on Bacto-agar. Germination decreased with increased concentrations of PDA, Phytagar and Agar No. 3, but remained constant on Agarose and Gelrite regardless of concentration. One percent Agarose was used as a medium for all subsequent experiments. Percentages of urediniospore germination increased rapidly after 1 h and reached highest level by 3 h. Elongation of germ tubes was fastest during the first 12 h and then became slower. Germ tubes elongated to about 120 'm in length at 24 h. Urediniospore germinated and germ-tube elongated at pHs 3.5 to 8.5, but the optimum pH was 4.5 to 7.0 for germination and 4.5 to 5.5 for germ-tube elongation. The results suggest that urediniospore germination and germ-tube elongation were nutrient independent.