First record of the clover cyst nematode Heterodera daverti in Serbia

Abstract

Clovers and other forage legumes are present in Serbia since ancient times. According to archaeobotanical data, clover seeds (Trifolium sp.) were found in the Neolithic locality of Starevo- Grad, dated from the Roman (Sarmatian) period. Clovers are valuable for their nutritional value, nitrogen fixation and honey production. Heterodera daverti Wouts and Sturhan is a cyst nematode belonging to the Schachtii species group. This species has been reported to cause severe losses to T. subterraneum L. Cysts are lemon-shaped, ambifenestrate, bullate, with a prominent vulval cone. The second-stage juvenile (J2) has a well-developed anteriorly concave stylet, oval median bulb and four incisures. The overall morphology, as well as host list are similar to other cyst nematode H. trifolii Goffart and perhaps some reports of H. trifolii may actually be H. daverti. Cysts of H. daverti were found in soil samples originating from Bzovik in southern Serbia, and examined at the Nematology laboratory of the Institute for Plant Protection and Environment. Nematodes were extracted using a Spears elutriator. For morphological studies, specimens were placed in lactoglycerol fixative and slides were prepared in glycerol. Photomicrographs were captured using an Olympus BH-2 microscope equipped with Nomarski contrast and Motic digital camera and software. Morphometrics of cysts and J2 were in agreement with the original description by Wouts and Sturhan. Genomic DNA was extracted from cysts with The Dneasy Blood and Tissue Kit and amplified with TW81 and AB28 primers. The obtained sequence of the ITS regions of this population (GenBank accession number PP101636) confirmed the identification of this species with 100% homology to H. daverti available in the NCBI database. To our knowledge, this is the first record of H. daverti in Serbia.