Abstract
Soybean (Glycine max) is one of the most important crops in the world. Phakopsora pachyrhizi is a plant pathogenic basidiomycete fungus that infects soybean, causing Asian Soybean Rust (ASR) disease and affecting production. Here, we describe how to prepare the plant material and the uredospore suspension (from spores harvested from leaves exhibiting sporulating uredinia) for in vitro leaf infection. Plant material is sprayed with the uredospore suspension and incubated for 12 days. During the incubation period, the presence of lesions and pustules is visually verified. After this incubation period, the leaves are classified according to the lesion type. The number of uredospores per CM2 of leaf was also estimated. The detached-leaf assay is routinely used to test fungicide efficiency (Scherb and Mehl, 2006). Detached-leaf, greenhouse and field results have been shown to be significantly correlated (Twizeyimana et al., 2007). The present protocol was adapted from the two publications cited above. The usefulness of this approach for studying P. pachyrhyzi infection on transgenic soybean was previously demonstrated by our research team (Wiebke-Strohm et al., 2012; Bencke-Malato et al., 2014).
Materials and Reagents
Equipment
Figure 2. Hand sprayer
Procedure
Notes
Recipes
Acknowledgments
We thank Dr. Emerson M. Del Ponte, Dr. Juliano dos Santos and Larissa Bittecourt for their technical assistance. This work was supported by grants from the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul (FAPERGS). The present protocol was adapted from Scherb and Mehl (2006) and Twizeyimana et al. (2007).
References
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