First Report on the Occurrence of Fusarium langsethiae Isolated from Wheat Kernels in Poland

Abstract

Numerous Fusarium species have been associated with Fusarium head blight of wheat. In Poland, Fusarium poae was reported as the dominant species isolated from wheat grain during seasons with low amounts of rainfall during anthesis (1). F. langsethiae was described as a new toxigenic Fusarium species (3) and causal agent of Fusarium head blight (2), which has been isolated from infected oats, wheat, and barley in northern and central Europe (Norway, Austria, Germany, Czech Republic, Denmark, and England) (2). On the basis of morphological similarities, F. langsethiae has long been identified as a “powdery” form of F. poae. However, F. langsethiae produces type A trichothecene toxins such as T-2, whereas F. poae produces nivalenol and other 8-keto trichothecenes, scirpentriol, and 15-acetoxyscirpenol. In 2006, we obtained several isolates of F. langsethiae from kernels collected from winter wheat ears with head blight symptoms. Isolates were collected in the central (Sobiejuchy 52°54′N, 17°43′E; Minikowo 53°29′N, 17°56′E) and northern (Radostowo 53°59′N, 18°45′E) regions of Poland. Strains were isolated on potato dextrose agar (PDA) medium (pH 5.5). Further analyses were conducted on single-spore isolates. Initial species identification of all isolates was conducted on the basis of morphological features. The strains were grown in darkness at 25°C on PDA in plastic petri dishes to diagnose colony color, odor, and growth rate. The cultures also were incubated on saltwater nutrient agar (SNA) at 25°C for 7 days in near-UV light (Philips TLD 36W/08) and darkness in a 12/12-h cycle to promote conidia formation. The calculated average mycelial growth rate per day was based on the difference in millimeters between the colony diameters after 4 and 7 days of incubation. Growth rates ranged from 5.4 to 10.3 mm/day for nine strains. Mycelium was whitish or pinkish white, sparse, and 1 to 3 mm high with no odor. All colonies showed a powdery mycelium surface. Microconidia was napiform or globose, nonseptate, sporadically 1-septate, with an average length of 6.4 μm (range 3.9 to 13.7 μm) and width of 5.6 μm (range 2.9 to 8.8 μm). Microconidia were formed in heads, borne on unbranched or branched monophialides that were 8.5 to 16.3 μm long. All strains had slim, bent monophialides, typical for F. langsethiae, and always a few, short, thick, and squat ones resembling F. poae. In young cultures, monophialides may be formed directly on hyphae. Formation of macroconidia, sclerotia, and chlamydospores were not observed after 3 weeks of incubation. Species identification was confirmed by PCR assay with the use of SCAR (sequence characterized amplified region) primers producing a 310-bp DNA fragment (4), which was deposited in GenBank (Accession No. EU088404). To our knowledge, this is the first report of F. langsethiae in Poland. References: (1) C. Sadowski et al. J. Appl. Genet. 43A:69, 2002. (2) M. Torp and A. Adler. Int. J. Food Microbiol. 95:241, 2004. (3) M. Torp and H. I. Nirenberg. Int. J. Food Microbiol. 95:247, 2004. (4) A. Wilson et al. FEMS Microbiol. Lett. 233:69, 2004.

Fusarium head blight (FHB) in Flanders: population diversity, inter-species associations and DON contamination in commercial winter wheat varieties

“…In view of interseasonal population dynamics it is possible that a new Fusarium species was introduced in the population in 2008. One of the possible candidates is F. langsethiae, a Fusarium species firstly described in 1999 (Torp and Langseth 1999) that has recently been reported by several authors as progressing in Eastern Europe (Hudec and Rohacik 2009;Lukanowski et al 2008;Torp and Nirenberg 2004).…”

“…The production of DON and NIV is mainly restricted to F. culmorum and F. graminearum although NIV can also be produced by F. poae (Quarta et al 2006). Fusarium graminearum particularly likes higher temperatures whereas F. culmorum, F. poae, F. avenaceum and M. nivale tend to dominate in cooler regions such as Scandinavia and the UK Lukanowski et al 2008;Parry et al 1995;Waalwijk et al 2003;Xu et al 2005). However, in European climates, temperature is not considered to be a limiting factor for the presence of FHB species.…”

“…In 1999, F. langsethiae was firstly characterised on cereals in Europe (Torp and Langseth 1999;Torp and Nirenberg 2004). In recent reports, the presence of F. langsethiae has been shown in several countries and is considered a major threat due to the production of T2-toxin (Hudec and Rohacik 2009;Lukanowski et al 2008).…”

Connection between primary Fusarium inoculum on gramineous weeds, crop residues and soil samples and the final population on wheat ears in Flanders, Belgium

“…Recently, a fast growing number of reports are describing the increasing importance of other species such as F. langsethiae, which was previously not associated with FHB in Europe (Lukanowski et al, 2008;Torp and Nirenberg, 2004). Many laboratories have devoted considerable effort to unequivocally delineate the Fusarium population, but the dynamics within the population seems inexhaustible.…”

Investigation of stored wheat mycoflora, reporting theFusarium cf.langsethiae in three provinces of Iran during 2007

“…Fusarium langsethiae described as a new toxigenic Fusarium species (Torp and Nirenberg, 2004), which has been isolated from oats, wheat and barly in northern, central and east Europe (Norway, Austria, Germany, The Netherlands, Czech Republic, Denmark, England, Italy and Poland) (Torp and Adler, 2004;Torp and Nirenberg, 2004;Infantino et al, 2007;Lukanowski et al, 2008). The basis of morphology is similar to Fusarium poae and identified as a "powdery" form of F. poae.…”