VIEW ARTICLE

Ecology and Epidemiology

Effect of Matric and Osmotic Potential on Teliospore Germination of Tilletia indica. M. Dupler, Research technician, Department of Plant Science, Utah State University, Logan 84322; J. L. Smilanick(2), and J. A. Hoffmann(3). (2)Research plant pathologist, Horticultural Crops Research Laboratory, U.S. Department of Agriculture, Agricultural Research Service, Fresno, CA 93727; (3)Research plant pathologist, Crops Research Laboratory, U.S. Department of Agriculture, Agricultural Research Service, Logan, UT 84322-6300. Phytopathology 77:594-598. Accepted for publication 9 June 1986. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1987.. DOI: 10.1094/Phyto-77-594.

The interaction of matric and osmotic water potential with temperature on the germination of teliospores of Tilletia indica was investigated on several substrates. Water potential was osmotically adjusted with KCl, NaCl, or sucrose, or matrically adjusted with polyethylene glycol 6000. Maximal germination on all osmoticants occurred at the highest potential tested (–1.4 bars); little or no germination occurred below –10.5 bars with NaCl or KCl, or below –14.5 bars with sucrose. Similarly, germination did not occur below –11.0 bars on polyethylene glycol 6000 and was reduced to less than 5% on soil below –15 bars. Optimal (15–20 C) or suboptimal (10 C) temperatures allowed greater germination at lowered osmotic potential compared with supraoptimal temperature (25 C). On pH adjusted soil or water agar, maximal germination occurred from pH 5.0 to 8.8 and was significantly reduced below 4.5.