Shady Soliman *1 , Moussa AlSamara1 , Mohamed Ahmed 2 and Nawal Ali 3
1Department of Environmental Protection, Higher Institute for Environmental Research, Latakia University, Latakia, Syria.
2 Plant Protection Department, Faculty of Agricultural Engineering, Latakia University, Latakia, Syria.
3 Department of Biology, Faculty of Science, Latakia University, Latakia, Syria.
(*Corresponding author: Shady Soliman. E-Mail shady-sm@outlook.com).
Received: 16/ 03/ 2025 Accepted: 23/ 11/ 2025
Abstract
Trichoderma harzianum is one of the most important biological control agents. It has a high parasitic capacity against economically important soil-borne fungal pathogens. It is also characterized by its high adaptability and ability to reproduce in diverse environmental conditions. The aim of this research was to study the effects of temperature, moisture, pH, and photoperiod on conidia production and biomass of Trichoderma harzianum. The results of the morphological and microscopic characterization of the isolate studied showed that its morphological description matched that of Trichoderma harzianum. The studied isolate gave the highest number of conidia 15.02±0.18 *109 spores/g at 30°C, and the average linear growth rate reached its highest levels 22.53±0.27 mm/day at the same temperature, while the studied isolate gave the highest dry weight of biomass 32±1.15 mg/g at 25°C. When testing the optimum pH, a significant increase was observed in the growth rate, average spore number, and percentage of inhibition with increasing pH up to 5.5, where it reached its peak of 24.4 ± 0.06 mm/day, 21.7 ± 0.88 * 109 spores/g, 57.1 ± 0.92%, respectively. These indicators decreased again with increasing pH. The 16:8 photoperiod treatment significantly outperformed the other treatments with an average spore number of 10.33 ± 0.17 * 109 spores/g. The average spore number at 25% moisture content was 2 ± 0.0 * 109 spores/g compared to 94.67 ± 2.2 * 109 spores/g at 55% moisture content, i.e., about 47 times.
Keywords:Trichoderma harzianum, conidial spores, growth rate, moisture content.
Full paper in Arabic: pdf