VIEW ARTICLE

Physiology and Biochemistry

Toxin Production by Fusarium solani From Fibrous Roots of Blight-Diseased Citrus. Robert A. Baker, Southern Region, U.S. Department of Agriculture, U.S. Citrus and Subtropical Products Laboratory, P.O. Box 1909, Winter Haven, FL 33880; James H. Tatum(2), and Stanley Nemec, Jr.(3). (2)Science and Education Administration, U.S. Citrus and Subtropical Products Laboratory, P.O. Box 1909, Winter Haven, FL 33880; (3)U.S. Horticultural Research Laboratory, 2120 Camden Road, Orlando, FL 32803. Phytopathology 71:951-954. Accepted for publication 24 December 1980. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1981. DOI: 10.1094/Phyto-71-951.

Single-spore isolates of Fusarium solani, obtained from fibrous roots of field-grown citrus trees exhibiting blight symptoms and from a dis-seased greenhouse-grown tree, were evaluated for toxin production. Several isolates from roots of blight-diseased trees produced culture extracts that severely inhibited root growth of radish seedlings. Inhibitory effect of extracts appeared to be due primarily to the presence of naphthoquinone derivatives. Toxins purified and identified from culture extracts included fusarubin, javanicin, and anhydrofusarubin; phytotoxicity was largely due to fusarubin.