Mediterranean cereal cyst nematode - Heterodera latipons
Effective: August 18, 2010 - December 31, 2019
Taxonomic Position: Tylenchida : Heteroderidae
Pest Type: Nematodes
Pest Code (NAPIS): NEFBCBH
This pest is a member of the following surveys: Cyst Nematode, Small Grains
These Approved Methods are appropriate for: 2019, 2018, 2017, 2016, 2015, 2014, 2013, 2012, 2011
Survey
Approved Method(s)
Method |
Detail |
NAPIS Survey Method |
Soil Sample |
Send sample to nematology diagnostic lab where nematodes will be extracted and identified (preferred method). |
3012 - General Soil Sample |
Tissue Sample |
Send sample to nematology diagnostic lab where nematodes will be extracted and identified. |
3011 - General Tissue Sample |
Method Notes: Laboratory methods that are acceptable for cyst extraction include sugar centrifugation, USDA cyst extractor, Fenwick can sieving, wet sieving, and elutriation.
Survey Recommendations
The following are recommendations for executing the survey using the approved methods for pest surveillance. The recommendations are developed through literature review and consultation with subject matter experts.
Signs: Before plant flowering, white lemon-shaped females can be observed on the roots by the naked eye or under a dissecting microscope after gently shaking or washing the roots to remove adhering soil.
Symptoms: Slight to severe yellowing of cereal stands can be observed at an early stage of an infestation. Later, infested fields show patchy plant growth associated with poor tillering and shorter spikes.
Symptoms occur in patches that enlarge as the nematode population increases. Plants also tend to wilt during warmer portions of the day.
Key Diagnostic or Identification
Approved Method(s)
ID/Diagnostic: Morphological: Keys are available for identification by morphological characteristics of the cyst, second-stage juvenile, male, and female.
Mulvey (1972) provides a key to 39 species of Heterodera, including H. latipons, based on characteristics of cysts.
Handoo (2002) provides a key to the species within the H. avenae group, as well as a thorough review of morphological studies to date.
Mistaken Identities: Heterodera latipons may occur by itself or in mixed populations that include closely related H. avenae or H. trifolii. H. latipons has been confused with several other cyst nematode species that parasitize cereals, including (but not limited to) H. avenae, H. bifenestra, H. filipjevi, H. hordecalis, H. mani, H. pakistanensis, H. torcomanica, H. zeae, and a more taxonomically distant species, Punctodera punctata.
Symptoms are similar to those caused by other biotic and abiotic stresses.
In Progress / Literature-based Diagnostics: Restriction fragment length polymorphism (RFLP), random amplified polymorphic DNA (RAPD), and internal transcribed spacer ribosomal DNA (ITS-rDNA) have all been used to differentiate morphologically similar species (Bekal et al., 1997; Subbotin et al., 1999; Subbotin et al., 2001; Nicol, 2002; Rivoal et al., 2003; Tahna Maafi et al., 2003; Madani et al., 2004; Abidou et al., 2005).
Toumi et al. (2013) developed a species specific PCR based on actin protein sequences that can detect H. latipons.
Heterodera latipons, H. avenae, H. filipjevi, and H. mani, were also differentiated by electrophoresis on cellulose acetate plates using the enzymes esterase and malate dehydrogenase and aliquots of 25 females (Mokabli et al., 2001).