Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 9/15/1999
Publication Date: N/A
Technical Abstract: Fusants were made between strains of Trichoderma virens and T. koningii. Two fusants that were morphologically identical to the T. koningii parent differed in a number of characteristics, including the production of antibiotics. The parent strain showed antibiosis against bacteria in the genera Bacillus and Agrobacterium and against the fungi Rhizoctonia solani and Pythium ultimum. The fusant strains also showed antibiotic activity against several bacteria and fungi. Some of the antagonistic activity to the bacteria and to Pythium ultimum was due to acidification of the media by T. koningii. However, chloroform extracts from these strains that were pH neutral also were active. The HPLC chromatograms from the chloroform extracts from the fusants differed significantly from that of the parent strain, suggesting the fusants differ from the parents in secondary metabolite production. The active fraction from the parent strain also differed in mobility on a TLC plate from the active fractions of the fusant progeny. Based on the UV spectra and GC-MS data, all the antibiotics appear to be related to the koninginin group of antibiotics.