Trichoderma uiride Isolated from Southern Leaf Blight-Infected Corn

During 1970. field corn produced in southern and midwestern United States was heavily infected with Helminthosporium maydis )iisikado and :v1iyake race T. the causative agent of southern corn leaf blight. The main secondary im'aders of the blighted corn were Trichoderma. Fusarium. and A.lternaria i.J. .J. Ellis. personal communication J. Several toxic compounds have been isolated from Trichoderma L'iride Pers. ex Fr .. such as gliotoxin (6). frequentin 1:31, and viridin I lJ. \Ve have isolated and purified a new mycotoxin from T. uiride )iRRL .'5:24:2. For convenience. we assigned the trivial name. trichotoxin A. to this new toxin. Another new mycotoxin. trichotoxin B. similar in chemical properties to trichotoxin A. \lias isolated from T. uiride )iRRL .'524:3: however. the yield was insufficient to determine its characteristics. This paper describes the isolation. purilication. and some properties of trichotoxin A. The T. uiride strains used in this investigation were isolated from various ears of Texas (Tl male-sterile corn: this corn was also heavily infected with H. mavdis race T. Ten different isolates of T. uiride grown on sterile corn for :3 weeks all produced trichotoxin A. Further studies of trichotoxin A production were conducted by growing these strains of Trichoderma in Fernbach flasks each containing .'500 ml of Raulin-Thorn medium and incubated statically at :25 C for 14 to 16 days. Of these. T. uiride )iRRL .'5242 was the best trichotoxin A producer. A chloroform-methanol i 1: 1. v/v) extract of