微生物与生化技术杂志

抽象的

Genetic Characterization of Trichoderma spp. Isolated from Different Locations of Menoufia, Egypt and Assessment of their Antagonistic Ability

El-Sobky MA, Fahmi AI*, Eissa RA, El-Zanaty AM

Trichoderma has been used as a biocontrol agent against soil borne diseases that cause economic losses for crops. The
objectives of the present investigation were (i) to isolate and characterize Trichoderma spp. from Menoufia Governorate
and (ii) to evaluate the isolated Trichoderma spp. as potential biocontrol agents against some soil borne diseases. Soil
samples were collected from nine districts and 25 isolates were obtained. Methods of identification of macroscopic
and microscopic features, and the sequences of ITS and TEF1-α yielded three species; T. harzianum, T. longibrachiatum
and T. asperellum. Phylogenetic tree of the identified 22 strains confirmed that the two strains T. longibrachiatum
and T. asperellum came together in the same branch while the rest of the strains which were T. harzianum were on
the other side of the tree. All 25 Trichoderma strains and isolates exhibited inhibition to the mycelial growth of four
pathogenens. They were antagonized by competition mechanism against 000v m Sclerotium spp., by antibiosis against
Fusarium oxysporum and partially against Sclerotium spp. and by mycoparasitism against Rhizoctonia solani. Also, they
elucidated differences in total chitinolytic activity measured by two different methods and exochitonolytic activity.
Finally, no correlation was found between total chitinolytic activities and total protein contents.