G. Soudi, L. El Ghadraoui, N. El Ghachtouli, M. Loukili, S. Amiri
Abstract: The cereal branch is one of the main agricultural production sectors in Morocco, including wheat, which represents the first speculation, given the size of the areas it covers. This culture faces many constraints that negatively affect its productivity. Among these constraints, we find fungal diseases including Fusarium wilt, which affects yields and sanitary quality of seeds. In order to promote the protection and the study of the phytosanitary status of wheat against Fusarium wilt, the Doukkala, Chaouia, Haouz, and Tadla regions are prospected to collect seed samples, while the Gharb-Chrarda-Bni-Hssen, Meknes-Tafilalet, and Fez-Boulemane regions were targeted to collect fresh samples at the heading stage, and that during the year 2013/2014. Thus the calculation of infestation levels, macro, microscopic and molecular identification by PCR was performed. The results obtained show that all the prospected regions were contaminated. For seed samples, durum wheat had higher levels of infections than soft wheat, which was not negligible. For durum wheat in the Doukkala, Haouz and Tadla regions, more than half of the samples had an average rate of Fusarium wilt infection, while 50 % of soft wheat seeds had low levels of infection. In Chaouia, 50 % of durum wheat samples were heavily infected, against 31 % only for soft wheat. For fresh samples, the results asserted that the most infected plots were those from Gharb, of which 40 % of the studied plots were highly infected, while the Meknes and Fez regions recorded the lowest infection rates.PCR molecular identification of seed samples isolates revealed the presence of two species responsible for Fusarium wilt, Microdochium nivalemajus and Fusarium avenaceum, with a dominance of Microdochium nivalemajus of over 90 %. Regarding the fresh samples, the species detected by PCR areMicrodochium nivalemajus with 42 % of dominance, followed by Fusarium culmorum: 40 % and finally Fusarium graminearum: 18 % for the region Gharb-Chrarda-Bni-Hssen. In the Mekns-Tafilalet and Fs-Boulemane regions, the only species that caused the infection is Fusarium avenaceum. We conclude from these results that the yield and sanitary quality of the crop incur significant risk due to Fusarium wilt, which damages the wheat crop by the presence of mycotoxins produced by Fusarium species in the grains.
Keywords: Seeds, Durum wheat, Soft wheat, Fresh samples, Heading stage, Fusarium wilt, Fusariumculmorum, Microdochiumnivale majus, Fusarium graminearum, Fusariumavenaceum, andMycotoxins