Colonization of soybean rust sori by Simplicillium lanosoniveum

In 2007, we isolated a filamentous fungus inhabiting sori of soybean rust (Phakopsora pachyrhizi) on soybean collected from Louisiana and Florida. This fungus was identified as Simplicillium lanosoniveum on the basis of ITS sequence data and morphological traits. S. lanosoniveum was found coiling within sori and around urediniospores. It showed a trophic attraction to rust sori, extending from sorus to sorus. It was not isolated from healthy leaf surfaces or within lesions of other diseases, nor was it isolated from commercial soybean fields where fungicides are routinely applied for control of diseases. Herein, we document for the first time the association between P. pachyrhizi and S. lanosoniveum.