The objective of this study was to determine the distribution frequency of the fungi associated with wheat (Triticum aestivum) crowns and roots in cereal producing areas of Turkey through a targeted survey of 518 commercial fields over a 2-year period. More than 26% of the fields had one or more of the fungal species commonly reported as part of the dryland root rot complex, Fusarium culmorum (14%) > Bipolaris sorokiniana (10%) > F. pseudograminearum (2%). The fungi considered to be part of the high rainfall root rot complex were found at very low frequencies: 2% for Gaeumannomyces graminis and 3% for Pythium spp. Species of Rhizoctonia were found in 22% of the fields. Several Fusarium species considered to be less or nonpathogenic to cereals were also found in high frequencies at 11% (F. oxysporum, F. chlamydosporum), 10% (F. sporotrichioides), and 8% (F. avenaceum and F. solani). The mostly random distribution of cereal root-rotting species across the survey area suggests the fungi are not distributed in any distinct agroecological relationship. As a result, the relative economic importance of a given species on wheat will be determined by a number of factors, such as their fungal pathogenicity, host susceptibility/tolerance, and the seasonal conditions. Results from this study suggest that there are a wide range of fungal species associated with root and crown tissues of wheat.

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Crown rot and head blight of wheat are caused by the same Fusarium species. To better understand their biology, this study has compared 30 isolates of the three dominant species using 13 pathogenic and saprophytic fitness measures including aggressiveness for the two diseases, saprophytic growth and fecundity and deoxynivalenol (DON) production from saprophytic colonization of grain and straw. Pathogenic fitness was generally linked to DON production in infected tissue. The superior crown rot fitness of Fusarium pseudograminearum was linked to high DON production in the stem base tissue, while Fusarium culmorum and Fusarium graminearum had superior head blight fitness with high DON production in grains. Within each species, some isolates had similar aggressiveness for both diseases but differed in DON production in infected tissue to indicate that more than one mechanism controlled aggressiveness. All three species produced more DON when infecting living host tissue compared with saprophytic colonization of grain or straw, but there were significant links between these saprophytic fitness components and aggressiveness. As necrotrophic pathogens spend a part of their life cycle on dead organic matter, saprophytic fitness is an important component of their overall fitness. Any management strategy must target weaknesses in both pathogenic fitness and saprophytic fitness.

Seedborne, nonpathogenic, fungal endophytes are commonly found in symbiotic relationships with many members of the cool‐season grass subfamily Pooideae The beneficial effects on plants possessing fungal endophytes, and the detrimental effects on consumers of fungal endophyte‐infected plants are widely known. The objective of our research was to determine if fungal endophytes exist in indigenous, wild Triticum (wheat) species from Turkey. From the Triticum species collected, we found two different fungal endophytes. Fungi identified morphologically as members of the genus Neotyphodium were found in the diploid Triticum species T. dichasians (Zhuk.) Bowden and T. tripsacoides (Jaub. & Spach) Bowden. The second endophyte, an Acremonium species, was found in T. columnare (Zhuk.) Morris & Sears, T. cylindricum Ces., T. monococcum L., T. neglecta Morris & Sears, T. recta Morris & Sears, T. triunciale (L.) Raspail, T. turgidum L., and T. umbellulatum (Zhuk.) Bowden. No fungal endophytes were found in T. kotschyi (Boiss.) Bowden, T. ovatum (L.) Raspail, T. peregrinum Morris & Sears, T. speltoides (Tausch) Gren. ex Richter, and T. tauschii (Coss.) Schmal., although the number of samples tested was small for some of these species. Both Acremonium endophyte‐infected and Acremonium endophyte‐free plants of T. triunciale were found to occur at different frequencies at four collection sites on the Anatolian Plateau. Through two selfed generations of the plants, it was found that the Neotyphodium endophyte was transmitted to 100% of the progeny of T. dichasians and T. tripsacoides However, the Acremonium endophytes were not transmitted in all plants that originally possessed them. We concluded that fungal endophytes of the genera Neotyphodium and Acremonium inhabit some wild wheat species grown indigenously in Turkey. These endophytes may influence the ecology and distribution of Triticum species, and may also serve as a source of biological control agents of pests or abiotic stress factors in wheat.

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Fusarium culmorum is a pathogen of economically important grain crops. In this work, Rep-PCR was used to identify genetic diversity in F. culmorum isolates which have been collected from wheat fields in Turkey. Reproducible genomic fingerprints were amplified in each strain by PCRs of prokaryotic repetitive extragenic palindromic (REP), enterobacterial repetitive intergenic consensus (ERIC) and BOX sequences. Totally 104 molecular markers were evaluated and similarity comparisons were shown as a dendrogram. The average genetic diversity was 52.3% ranging from 15.8% to 88.7% according to the Rep-PCR data. Cluster analysis showed agreement with the distance of sampling locations. The highest genetic similarity (84.2%) was determined between two F. culmorum isolates (F1 and F2) originated from the same agro-ecological region. Our results showed that Rep-PCR is convenient and rapid for genetic diversity analyses and strain differentiation in F. culmorum.