Browsing by Author "Djebaili, Rihab"

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Genetic Diversity of Trichoderma Harzianum Isolates in Sunflower Rhizosphere: the Application of the Urp Molecular Marker
(Mdpi, 2022) Danesh, Younes Rezaee; Pellegrini, Marika; Kariman, Khalil; Boyno, Gokhan; Djebaili, Rihab; Farda, Beatrice; Najafi, Solmaz
The genetic diversity of 77 Trichoderma harzianum isolates collected from sunflower rhizosphere soils in Urmia, Khoy, and Salmas in West Azerbaijan province, Iran, was evaluated by using the Universal Rice Primer (URP) molecular marker. The DNA band pattern of the isolates was developed using seven primers of this marker. These primers produced 186 gene loci, out of which 182 loci were polymorphic. Accordingly, the genetic diversity of the isolates was calculated, and their kinship relations were determined by cluster analysis using the NTSYS software package. URP-6R had the highest marker index among the studied primers, followed by URP-1F, URP-4R, and URP-25F, implying their higher efficiency in discriminating between the isolates. The results showed that the URP marker could discriminate between isolates using macroscopic morphological characteristics, such as color and colony type, potential of pigment production in the culture medium, and colony growth rate. Furthermore, there was no significant relationship between the geographical distribution of the isolates and the band patterns generated by the primers except for a few cases. The results generally revealed that the URP marker was an efficient tool for determining the genetic diversity of T. harzianum.
Onion Fusarium Basal Rot Disease Control by Arbuscular Mycorrhizal Fungi and Trichoderma Harzianum
(Mdpi, 2024) Yagmur, Abdulaziz; Demir, Semra; Canpolat, Sirel; Rezaee Danesh, Younes; Farda, Beatrice; Djebaili, Rihab; Pellegrini, Marika
Soilborne pathogens reduce 60% of the yield of onion crops. A common fungal pathogen causing wilt disease and severe losses is Fusarium basal rot (FBR). In this study, the combination of Arbuscular Mycorrhizal Fungi (AMF) with Trichoderma harzianum was investigated against FBR. Onion samples were collected from the Ankara-Polatl & imath; region. Among the isolates, isolate S6 was identified as F. oxysporum f. sp. cepae (FOC) using morphological and molecular methods and pathogenicity tests. Different combinations of AMF (Funneliformis mosseae pure strain and the commercial AMF) and T. harzianum were inoculated on susceptible onion cultivars (Se & ccedil;, Gence, and & Scedil;ampiyon). The effects of the treatments on FOC biocontrol were studied under growth chamber conditions. The results showed that & Scedil;ampiyon was the most resistant, while Gence was the most susceptible to basal rot disease. Different colonization rates (8.91-24%), spore densities (16.4-50.4 spore/10 g soil), and the extent to which a plant needs mycorrhizal conditions to grow to its maximum potential (i.e., mycorrhizal dependencies-18.3-51.9%) were recorded by treatment. Both single and combined applications of AMF and Trichoderma applications suppressed FOC. Suppressive effects were more pronounced when the F. mosseae pure strain was used alone (when F. mosseae was used, disease severity decreased from 90 to 68%, p < 0.05). The F. mosseae pure strain also showed the best plant growth promotion and phosphorus content release. The results indicate an interesting potential use of F. mosseae and the combination of AMF with T. harzianum in the management of FOC in onions.