FINGERPRINTING REVEALS GAMMA-RAY INDUCED MUTATIONS IN FUNGAL DNA - IMPLICATIONS FOR IDENTIFICATION OF PATENT STRAINS OF TRICHODERMA-HARZIANUM

We have analyzed different patent strains and gamma-ray induced mutant s of Trichoderma harzianum by DNA fingerprinting and PCR fingerprintin g (RAPD). Applying wild-type phage M13 DNA, with the oligonucleotides (CT)(8) and (GTG)(5) as probes for hybridization, as well as the oligo nucleotides GGCATCGGCC, (GTG)(5), (CAC)(5) and the M13 sequence GAGGGT GGCGGTTCT as primers in PCR, we were able to obtain different and disc riminative fingerprint patterns for all strains and mutants investigat ed. Irradiation of fungi led to mutations which resulted in new finger print patterns. Consequently, irradiation-induced mutants can be clear ly distinguished from the original wild-type isolates by genomic finge rprinting which is of importance for the patent protection of fungal s trains. Sequencing of the ITS-1 and ITS-2 regions of the rDNA gene com plex revealed the same sequence for all mutant strains and the origina l wild-type strain.