The effect of urea, sulfate ammonium, nitrate potassium and horse manure on S. rolfsii was tested in vitro, alone and in combination with T. harzianum. Tests on liquid culture media showed that Sclerotium rolfsii did not utilize urea as a source of nitrogen while sulfate ammonium and nitrate potassium allowed the growth of the fungus. On a solid medium, the fertilizers at rates of 12 g N•m-2 and 18 g N•m-2 had an inhibitory effect on the growth of Sclerotium rolfsii mycelium. The highest effect was observed for urea. In contrast, Trichoderma harzianum assimilated all fertilizers but had a preference for sulfate ammonium. The antagonistic activity of Trichoderma harzianum on Sclerotium rolfsii on solid culture media was stimulated in the presence of the three nitrogen sources. The horse manure at high rates inhibited the growth of S. rolfsii, favored the development of T. harzianum and enhanced its antagonistic effect on S. rolfsii. The confrontation of Trichoderma harzianum with sclerotia of Sclerotium rolfsii in soil fertilized separately with urea, sulfate ammonium, nitrate potassium or manure showed an increase in the antagonistic activity. Particularly, the manure in combination with T. harzianum induced high mortality of sclerotia of the fungus. In the agronomic context of the region of Doukkala, it seems adequate to add these nitrogen sources to contribute to the biological control of Sclerotium rolfsii.

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The genetic variability and collection structure of the wheat leaf rust fungus Puccinia recondita collected from four agro-ecological areas of Morocco, Abdadoukala, Chaouia-Tadla, Gharb and Tange´rois were investigated by amplified fragment length polymorphism (AFLP) markers. A set of five AFLP primers combinations which generated 253 polymorphic loci were used. Hierarchical partitioning revealed that bread wheat collections of Puccinia recondita form a single collection. No significant variation was observed between durum wheat collections of Puccinia recondita; they maintained most of the genetic variability within rather among collections. The distribution pattern of genetic variation of Puccinia recondita collections seems to be the result of high gene flow and the mixed reproduction system.

The Trichoderma fungal species and the bacteria Bacillus species were described as inducers of plant systemic resistance in relation to their antagonistic activity. The objective of this study was to evaluate the effect of selected strains of Bacillus amyloliquefaciens (I3) and Trichoderma harzianum (A) on inducing systemic resistance in Arabidopsis thaliana as a model for plant molecular genetics. The microorganisms were identified and were confirmed for their antagonistic potential in vitro and in vivo in previous studies. In order to explore this mechanism, two mutants of A. thaliana carrying a PR1 promoter (a conventional marker of salicylic acid (SA) pathway) and LOX2 promoter (a marker triggering jasmonic acid (JA) pathway activation) were analyzed after inoculating antagonists. Transgenic reporter line analysis demonstrated that B. amyloliquefaciens I3 and T. harzianum A induce A. thaliana defense pathways by activating SA and JA at a high level compared to lines treated with chemical elicitors of references (acibenzolar-S-methyl (Bion 50 WG (water-dispersible granule)), SA, and methyl jasmonate). The efficacy of B. amyloliquefaciens I3 and T. harzianum A in inducing the defense mechanism in A. thaliana was demonstrated in this study.