Inhibitory effect of Pinus brutia Ten. resin on fungi isolated from some forest tree seeds in vitro

The study was conducted in the Entomology and Plant Pathology Laboratory, Department of Forestry Sciences, College of Agriculture and Forestry, University of Mosul, to study and identify the fungi associated with some forest tree seeds. The identified fungi were Penicillium sp., Aspergillus sp., Rhizopus sp., Fusarium sp., Macrophomina phaseolina, Phomasp., and Alternaria sp. The results of the isolation showed that the highest isolation rate was recorded for the fungus Rhizopus sp. (46.66%) on the seeds of Eldarica pine (Pinus eldarica), as well as Penicillium sp. at the same rate on the seeds of Italian cypress (Cupressus sempervirens). The lowest isolation rate was recorded for the fungi Alternaria sp., Fusarium sp., and Macrophomina phaseolina (6.66%) on the seeds of Eldarica pine (Pinus eldarica), Brutia pine (Pinus brutia), and Eastern arborvitae (Biota orientalis). The effect of different concentrations of natural pine resin showed that the fourth concentration (40%) had a significant effect in inhibiting all fungi. The highest inhibition rate was recorded for the fungi Alternaria sp. and Fusarium sp. at the fourth concentration, reaching 100% for both fungi. The lowest inhibition rate was recorded for Macrophomina phaseolina, which was 0% at both the first and second concentrations, which did not differ significantly from the control treatment.Regarding Phoma sp., the highest inhibition rate was 86.11% at the fourth concentration, while the lowest inhibition rate was 40.55%. Inhibition increased with increasing concentrations of natural resin against pathogenic fungi, as it had an effect on the fungal cell and mycelium. These changes are associated with the loss of strength of the cell wall, which is responsible for the integrity of the cell shape .The 40% concentration was the best for inhibiting all fungi, and the effect of these natural extracts increased with increasing concentration