First Report of the Cereal Cyst Nematode Heterodera filipjevi on Wheat in Serbia

The most globally recognized and economically important nematode on wheat is the cereal cyst nematode (CCN) complex (1). One of the most important species of this group is Heterodera filipjevi (Madžidov, 1981) Mulvey and Golden, 1983. During regular soil quarantine control in September 2010, Heterodera sp. cysts were found in soil samples originating from a wheat field in Gunaroš, Vojvodina Province, in northern Serbia. The wheat was a winter crop grown in a dryland production system and had an average cyst density of 2.50/100 cm³ of soil. Morphologically, the cysts were golden brown and lemon shaped with a posterior protuberance. The vulval cone was bifenestrate with horseshoe-shaped semifenestra, bullae, and underbridge. Cyst measurements (n = 30) ranged as follows: cyst length (without neck): 511.50 to 899.00 μm, cyst width: 201.50 to 682.00 μm, fenestral length: 44.80 to 65.60 μm, fenestral width: 24.00 to 40.00 μm, vulval bridge length: 12.80 to 20.80 μm, vulval bridge width: 6.40 to 14.40 μm, vulval slit: 6.00 to 12.80 μm, and underbridge length: 60.00 to 112.00 μm. The second-stage juveniles had an offset head, stylet with characteristic anchor-shaped basal knobs, four incisures, and a conical tail with a rounded tip. The J₂ morphometrics (n = 30) were: length: 447.30 to 611.10 μm, width: 22.40 to 25.60 μm, stylet: 20.80 to 24.00 μm, tail length: 56.00 to 68.80 μm, tail width: 14.40 to 19.20 μm, and hyaline length: 35.20 to 44.80 μm. The ITS region was used for molecular analysis. Each DNA sample was extracted from a single cyst. Sequencing was done with primers TW81 and AB28 (2). In comparison with other H. filipjevi populations, the obtained sequence (GenBank Accession No. JX235959) revealed 99 to 100% similarity. Morphological and molecular data confirmed the existence of H. filipjevi. This is, to our knowledge, the first report of H. filipjevi from Serbia. Since wheat has important socioeconomic value for Serbia, after extensive surveys, additional phytosanitary measures may be necessary to prevent the spread of this parasite. References: (1) J. M. Nicol et al. Current Nematode Threats to World Agriculture. Genomics and Molecular Genetics of Plant-Nematode Interactions, Springer, New York, 2011. (2) A. M. Skantar et al. J. Nematol. 39:133, 2007.