Universally primed PCR (UP-PCR) fingerprinting combined with
UP-PCR product 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 closely related strains and as tools to
group strains which is necessary to facilitate; (2) identification of
markers for development of specific 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 hybridization
using UP-PCR amplification products, was used to group them into
15 genetic entities. ITS1 ribotyping of the strains was performed by
digestion of the PCR amplified rDNA spacer region and
electrophoresis 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 ITS1 based groups proved to be consistent,
but the resolution of the UP-PCR based approach was superior. The
results demonstrate that the combination of UP-PCR and
ribotyping can aid in clarifying species distinction in Trichoderma
and Gliocladium and has the potential to become a valuable tool
for
studies of diversity and genetic structure of populations
of these fungi. Furthermore, identification of single strains by the specific
UP-PCR fingerprint seems feasible.