Keywords : Trichoderma

The Effect of Biological Control Agents on Fungi Isolated from some Citrus Trees in Mosul

Maha M. Taha Al-Nuaimy; Faten N. Mula Abed

Rafidain Journal of Science, 2021, Volume 30, Issue 1, Pages 68-77
DOI: 10.33899/rjs.2021.167687

In this study, the counter effect of two Biological Control Agents, namely Trichoderma harzianum fungi and Bcillus subtilis bacteria against the fungi-like organism Phytophthora infestans and the fungi; Fosarium solani and Rhizoctonia solani isolated from orange- trees’ bark and from lemon- trees’ roots. The results showed that the counter effect of T. harzianum (using double culture on petri dishes) reached 1.0 according to Bell scale, against all these pathogens. The counter effect of this antibiotic was also tested in vitro on branches taken from citrus trees and infected with Phytophthora infestans. The infection percentagesbefore treatment with T. harzianum were 75% and 58.3% for the branches isolated from lemon trees and orange trees respectively, whereas after treatment with the inhibition fungi, the percentages of infection were 25% and 16.6% for the branches isolated from lemon trees and orange trees respectively. The percentages of inhibition by Bacillus subtilis bacteria were 83%, 71% and 73% against Phytophthora infestans , Fusarium solani and Rhizoctonia solani respectively

Trichoderma Isolates Ability to Produce Cellulase Enzyme and it's Role as Resistance Inducer to FungusMacrophomina phaseolina

Nihal Y. Al-Murad

Rafidain Journal of Science, 2011, Volume 22, Issue 6, Pages 46-59
DOI: 10.33899/rjs.2011.6522

The result of this study indicated that Trichoderma spp. culture filtrates have antagonistic activity against Macrophomina phaseolina where the isolate Tv1 gave the higher antagonistic activity with 66%. in addition to that the same isolates showed higher antibiosis activity with an average of 1 according to Bell scale, with reduced pH level in culture media while the isolate Thk20 recorded the higher biomass amount of 1.17 g/100 mL with sporeulation ability 7,58 /cm2. Trichoderma isolates showed significant differences in it's capacity to produce cellulase enzyme where the isolate TV1 produced the higher amount of enzyme 1,26 unit/g, followed by the isolates Tv2, Th1, Thk20 with 0.88, 0.28 , 0.28 unit/gm respectively. The result also showed that the ability of Trichoderma isolates to induce resistance in cowpea plants by raising in peroxidase activity to 1.52 unit /g f.w in Tv2 and in polyphenol oxidase activity with 3.03 in the same isolate treatment in addition to the pathogen with the isolate Thk20 recorded the higher amount of total phenols in plant 1.51 mg/g.f.w and 1.46 mg/g.f.w in the same isolate treatment in presence of the pathogen