|Effects of Climate Change on the Components of Wheat Leaf Rust Disease on Winter Wheat.|
A. M. MASHAHEET (1), D. S. Marshall (2), K. O. Burkey (2). (1) North Carolina State Univ, Raleigh, NC, U.S.A.; (2) North Carolina State University, Raleigh, NC, U.S.A.
Understanding climate change effects on wheat leaf rust (caused by <i>Puccinia recondita)</i> is important for maintaining yield. Four winter wheat genotypes known to differ in their response to leaf rust were grown under combinations of CO2 (400, 570 ppm) and O3 (10, 50 ppb), major components of climate change. Plants were inoculated with leaf rust spores at Zadoks growth stage of 39-40. Plant growth, ozone injury and disease development were documented throughout the growing season. Results showed that elevated levels of both gases, singly and in combination, accelerated plant development. Foliar injury from O3 was observed in all genotypes and elevated CO2 ameliorated this effect. Ozone concentrations utilized were not high enough to affect yield, plant height, or vegetative dry weight, but elevated CO2 and the combination of gases (O3+CO2) increased each of these parameters. Rust infection decreased plant yield, height and the vegetative dry weight. Elevated CO2 partially reduced yield loss from rust infection, but did not alter rust effects on height and vegetative dry weight. In terms of gas effects of disease progression, O3 increased disease severity and pustule size but CO2 effects were not significant. The genotype x rust x gas interaction was not significant.