Fusarium is one of the most important pathogenic and toxigenic fungi widely distributed all over the world, including Iran. Fusarium species are found frequently in stored agriculture products especially wheat. The objective of this study was to identify Fusarium species associated with stored wheat seeds and their pathogenicity on root and head of wheat in Kermanshah, the leading province in wheat production in Iran. In this survey 75 seed samples of stored wheat were collected from 10 different regions during 2006-2008 and tested for the presence of Fusarium. Fusarium spp. were found in 51 (68%) of 75 samples. A total of 580 Fusarium strains were isolated, identified and preserved. All these strains belong to 20 Fusarium spp. according to morphological characters. Each conidial suspension of selected strains representing all species was evaluated for their pathogenicity on roots and spikes of healthy wheat var. Fallat in the greenhouse. F. graminearum, F. crookwellense, F. trichothecioides, F. culmorum and F. verticillioides were the most pathogenic to wheat's head. Foot rot assessment revealed that F. pseudograminearum and F. culmorum were the most damaging species. Of the Fusarium isolates, F. graminearum was the most prevalent followed by F. verticillioides and F. proliferatum. This is the first comprehensive report on identity and distribution of Fusarium spp. from stored wheat seeds in Iran while F. nelsonii was reported for the first time from wheat seeds in Iran.
Fusarium is one of the important phytopathogenic genera of microfungi causing serious losses on cucurbit plants in Kermanshah province, the largest area of cucurbits plantation in Iran. Therefore, the objectives in this study were to isolate and identify disease-causing Fusarium spp. from infected cucurbit plants, to ascertain their pathogenicity, and to determine their phylogenetic relationships. A total of 100 Fusarium isolates were obtained from diseased cucurbit plants collected from fields in different geographic regions in Kermanshah province, Iran. According to morphological characters, all isolates were identified as Fusarium oxysporum, Fusarium proliferatum, Fusarium equiseti, Fusarium semitectum and Fusarium solani. All isolates of the five Fusarium spp. were evaluated for their pathogenicity on healthy cucumber (Cucumis sativus) and honeydew melon (Cucumis melo) seedlings in the glasshouse. F. oxysporum caused damping-off in 20-35 days on both cucurbit seedlings tested. Typical stem rot symptoms were observed within 15 days after inoculation with F. solani on both seedlings. Based on the internal transcribed spacer (ITS) regions of ribosomal DNA (rDNA) restriction fragment length polymorphism (RFLP) analysis, the five Fusarium species were divided into two major groups. In particular, isolates belonging to the F. solani species complex (FSSC) were separated into two RFLP types. Grouping among Fusarium strains derived from restriction analysis was in agreement with criteria used in morphological classification. Therefore, the PCR-ITS-RFLP method provides a simple and rapid procedure for the differentiation of Fusarium strains at species level. This is the first report on identification and pathogenicity of major plant pathogenic Fusarium spp. causing root and stem rot on cucurbits in Iran.
Scientific communication is facilitated by a data-driven, scientifically sound taxonomy that considers the end-user's needs and established successful practice. In 2013, the Fusarium community voiced near unanimous support for a concept of Fusarium that represented a clade comprising all agriculturally and clinically important Fusarium species, including the F. solani species complex (FSSC). Subsequently, this concept was challenged in 2015 by one research group who proposed dividing the genus Fusarium into seven genera, including the FSSC described as members of the genus Neocosmospora, with subsequent justification in 2018 based on claims that the 2013 concept of Fusarium is polyphyletic. Here, we test this claim and provide a phylogeny based on exonic nucleotide sequences of 19 orthologous protein-coding genes that strongly support the monophyly of Fusarium including the FSSC. We reassert the practical and scientific argument in support of a genus Fusarium that includes the FSSC and several other basal lineages, consistent with the longstanding use of this name among plant pathologists, medical mycologists, quarantine officials, regulatory agencies, students, and researchers with a stake in its taxonomy. In recognition of this monophyly, 40 species described as genus Neocosmospora were recombined in genus Fusarium, and nine others were renamed Fusarium. Here the global Fusarium community voices strong support for the inclusion of the FSSC in Fusarium, as it remains the best scientific, nomenclatural, and practical taxonomic option available.