Assessment of Comparative Virulence and Resistance in Soybean Using Field Isolates of Soybean Rust
Loading...
Date
2013-04-15
Journal Title
Journal ISSN
Volume Title
Publisher
Canadian Center of Science and Education
Abstract
A major impediment to breeding for resistance to Asian soybean rust (Phakopsora pachyrhizi) is the lack of stable
sources of resistance, due to high variability in the pathogen. The objectives of this study were to assess
comparative virulence of five diverse field isolates from major soybean producing areas in Uganda, and identify
lines with resistance to isolates of soybean rust in seedling and adult plants under screen house and field conditions
respectively. When inoculated with the five field isolates, all twelve lines evaluated showed diverse and mixed
reactions, suggesting each location differed in soybean rust races and/or virulence. Experimental sites growing
many diverse soybean lines yearly had the greatest diversity of soybean rust. The effectiveness of specific
resistance genes was restricted to certain locations and gene Rpp2 previously resistant was ineffective producing a
susceptible tan reaction at the seedling stage. A positive correlation between mean lesion density at the seedling
stage and adult plant severity indicated that using field isolates to screen for seedling resistance can be a useful
breeding approach to extrapolate resistance in adult plants. Overall, these results emphasise the relevance of using
field isolates from the target areas to evaluate lines for soybean rust resistance.
Description
Keywords
Citation
Maphosa, M., Talwana, H., & Tukamuhabwa, P. (2013). Assessment of comparative virulence and resistance in soybean using field isolates of soybean rust.