Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 4/11/2008
Publication Date: 6/1/2008
Citation: Slaminko, T.L., Hartman, G.L. 2008. Host range of Phakopsora pachyrhizi, the causal agent of soybean rust [abstract]. Phytopathology. 98:S147.
Technical Abstract: Phakopsora pachyrhizi, the causal organism of soybean rust, was first described in 1903 from leaves of Glycine max subsp. soja, or wild soybean, in Japan. Since that time, there have been numerous reports of the pathogen on various leguminous species around the world, first in Asia, followed by Australia, Africa, South America, and most recently North America. Prior to its introduction to North America in 2004, P. pachyrhizi was reported on approximately 90 host species, but the consolidation of some species decreased the number to 77 legume hosts in 41 genera. After 2004, a greenhouse evaluation of 176 papilionoid legumes inoculated with a mixture of four international isolates of P. pachyrhizi in Ft. Detrick, MD greatly expanded the known host range by 65 species and 12 genera, and a subsequent field evaluation added five species and two subspecies. Lesion type and degree of sporulation varied by host, and several hosts had as much sporulation as susceptible soybean types. P. pachyrhizi is currently reported to occur on approximately 150 species in 53 genera of the legume family Fabaceae. The host species all belong to a monophyletic group within the Papilionoideae subfamily. Approximately 120 of the known hosts of P. pachyrhizi grow in North America and may play a role in the epidemiology of the disease as overwintering hosts or sources of inoculum to soybean.