UP-PCR ANALYSIS AND ITS1 RIBOTYPING OF STRAINS OF TRICHODERMA AND GLIOCLADIUM

Universally primed PCR (UP-PCR) fingerprinting combined with UP-PCR pr oduct cross hybridization, and ITS1 ribotyping were used to study the genetic relatedness of strains of Trichoderma and Gliocladium for two purposes: (1) to evaluate the ability of the methods to discriminate c losely related strains and as tools to group strains which is necessar y to facilitate; (2) identification of markers for development of spec ific detection assays for selected strains. Included among the strains were one T. harzianum, two T. virens, and one G. roseum that had been selected previously for their antagonistic ability against soil-borne phytopathogens. Similarity among strains, found by cross dot blot hyb ridization using UP-PCR amplification products, was used to group them into 15 genetic entities. ITS1 ribotyping of the strains was performe d by digestion of the PCR amplified rDNA spacer region and electrophor esis of the products. The differences obtained from ribotyping as well as the differences in mobility of the intact spacer region were used for grouping of the strains. The UP-PCR hybridization groups and the I TS1 based groups proved to be consistent, but the resolution of the UP -PCR based approach was superior. The results demonstrate that the com bination of UP-PCR and ribotyping can aid in clarifying species distin ction in Trichoderma and Gliocladium and has the potential to become a valuable tool for studies of diversity and genetic structure of popul ations of these fungi. Furthermore, identification of single strains b y the specific UP-PCR fingerprint seems feasible.