|Molecular technology as a useful tool for nematode diagnostics: A case study of root-lesion nematode and cereal cyst nematode|
G. P. YAN (1). (1) North Dakota State University, Department of Plant Pathology, Fargo, ND, U.S.A.
Plant-parasitic nematodes are an important group of pests that affect agricultural production. Accurate identification of nematode species and awareness of population density are critical for designing effective control measures. Morphological identification of nematode species is difficult due to morphological similarity, overlapping morphometric measurements, and great variability of individual specimens. Molecular techniques offer opportunities for identifying and quantifying species of nematodes to an extent that could not be achieved with morphological diagnostics. PCR-RFLP was optimized to identify cereal cyst nematodes affecting wheat in the Pacific Northwest (PNW), which led to the first detection of the cyst nematode <i>Heterodera filipjevi</i> in Oregon. Discovery of <i>H. filipjevi</i> in Oregon represented a new record for the occurrence of that species in North America. Less expensive species-specific PCR was developed for identifying field samples infested with cyst nematodes, which led to the first discovery of <i>H</i>. <i> filipjevi</i> in Washington. Real-time PCR assays were developed to detect and quantify the root-lesion nematodes <i>Pratylenchus neglectus</i> and <i>P. thornei</i> restricting wheat production in non-irrigated PNW fields. Real-time PCR provides a useful platform for efficient detection and quantification of nematodes directly from soil and plants, which has the potential to allow us to avoid traditional nematode extraction, microscopic identification and counting steps.