The chemical composition of essential oils isolated by hydrodistillation from the aerial parts of Tunisian Pinus pinea Linn. was analyzed by GC and GC/MS. Sixty-six compounds were identified, representing 98.5% of total oil, which was found to be rich in monoterpene hydrocarbons (73.1%) particularly limonene (54.1%), a-pinene (7.7%), and b-pinene (3.4%). The yield and the physico-chemical properties were determined. Results of the antifungal activity study by in vitro contact assay showed that P. pinea oil significantly inhibited the growth of ten plant pathogenic fungi. Moreover, herbicidal properties of the oil, tested on Sinapis arvensis L., Lolium rigidum Gaud., and Raphanus raphanistrum L., indicated that the oil completely inhibited the seed germination at a high concentration, while at low doses the oil acted by decreasing and delaying the germination and inhibiting the seedling growth of all tested weeds unlike the commercial herbicide. Our results showed that P. pinea essential oil could be valorized as bioproduct for biocontrol of weeds and fungal plant diseases.

Background Fusarium crown rot is one of the major diseases that cause significant yield losses of wheat, and Trichoderma strains were known as an effective biocontrol agent. Main body The aim of this study was to evaluate the potential of coating durum wheat seeds of the cultivar “Karim” with 3 different Tunisian strains of Trichoderma sp. (S.INAT, SIO1, SIO2) and the Trichoderma-based commercial product Trianum-T22 on seed germination, seedling growth, and plant defense response against the pathogen Fusarium culmorum. The strains were identified using molecular tools based on sequencing ITS region of ribosomal DNA. The results confirmed at 99% of homology that the strains were T. harzianum. Under controlled conditions, the coating seeds were released with 400 μl of spore suspension at 107 spores/ml. The seed coating with Trianum-P, and S.INAT showed the highest seed germination rates ranging from 85 to 90% while S.IO1 and S.IO2 presented the lowest germination rates with 66 and 68%, respectively. At 20 days post-infection (dpi) with F. culmorum, the treated plants with S.INAT and Trianum-T22 reduced the disease incidence by 53.59 and 51.79%, respectively than the control. Besides, S.INAT induced two-folds the phenolic compounds level compared to infected control. Further, the peroxidase activity was enhanced by 50% in average since 10 dpi in plants treated with S.INAT and SIO2 than the control. Conclusion The results suggest that seed coating with T. harzianum S.INAT was a promising tool for crop production and protection under field conditions due to both direct antagonist activity and the indirect growth promotion. This strain seems to induce the systemic resistance of plants against foot crown rot disease.

No abstract

No abstract

No abstract