الفهرس | Only 14 pages are availabe for public view |
Abstract Hydrolytic enzyme producing Trichoderma species have long been recognized as an agent for controlling plant diseases caused by various phytopathogenic fungi. A study was intended to characterize twenty isolates of Trichoderma isolated from the rhizosphere of different crop plants to characterize and identify certain biocontrol related genes (chitinase and cellulase genes). Morphological and molecular characterization of antagonistic ability of Trichoderma species were studied. On the basis of morphological and cultural characteristics, the Trichoderma isolates were identified as T. harzianum (10 isolates), T. koningii (8 isolates), and T. viride (2 isolates). This result was in accordance with the result obtained from the DNA sequence data analysis of internal transcribed spacer (ITS region) of rDNA. ITS-PCR of rDNA region with ITS1 and ITS4 primers produced 560-600 bp products in all isolates. This result indicated the identification patterns of Trichoderma isolates, the amplified DNA was sequenced and aligned against ex-type strain sequences from Tricho BLAST and established Trichoderma taxonomy. Five isolates were positively identified as Trichoderma koningii and one as Trichoderma harzianum. Amplification of ITS region of the rDNA has showed potential as a rapid technique for successfully identifying Trichoderma species in all cases. Phylogenetic analysis based on ITS region of rDNA sequences, including of 6 biocontrol Trichoderma strains and the sequences of 15 other Trichoderma spp. obtained from sequence databanks type strains of different species, clustered the 21 Trichoderma strains into four groups: T. koningii- Hypocera koningii; Trichoderma koningii FUE9, Hypocrea koningii-AF538622; Trichoderma koningii I18 and Trichoderma harzianum-FUE15. |