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Date: May 2009
Source: British Society for Plant Pathology, New Disease Reports [edited] <http://www.bspp.org.uk/publications/new-disease-reports/ndr.php?id=019038>


[Ref: M Gitty, Z Tanha Maafi. First report of a potato cyst nematode, _Globodera rostochiensis_, on potato, in Iran. BSPP New Disease Reports
2009 (Feb-Aug); 19]

In June 2008 a few ware potato fields in Hamadan Province in the western part of Iran showed patches of about 20-200 square metres of poor growth.
Potato plants in these areas exhibited symptoms of severe stunting and nutrient deficiency along with yellow leaves and wilting (figure 1 in URL above: patches of infested potato field showing poor growth). Roots of infested plants showed white, golden mature [nematode] females and brown cysts on their surface (figure 2 in URL above: mature females and cysts of potato cyst nematode, _Globodera rostochiensis_ on the root surface of potato plant). Cysts and 2nd stage juveniles were extracted from soil and root samples.

The morphological and morphometrical characters of 2nd stages juveniles and perineal area of cysts were examined by light microscope. The cysts showed the general characteristics of _Globodera_ genus -- that is, almost spherical body without vulval cone, circumfenestrate opening of the perineal area and subterminal anus. 2nd stage juveniles had stylets with rounded knobs.

A molecular test [species specific polymerase chain reaction] was done. On the basis of the results obtained the cysts were identified as _Globodera rostochiensis_ [Wollenweber, 1923 (Behrens, 1975)]. The morphological diagnosis was confirmed by amplifying a single fragment of 315 base pair length. No amplification was produced with the specific primers for _G. pallida_. Potato cyst nematodes (PCNs) are considered quarantine pests in Iran and this is the first report of the genus _Globodera_ and _G. rostochiensis_ from Iran.

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[Both golden (_Globodera rostochiensis_, with at least 5 races) and pale (_G. pallida_) potato cyst nematodes (PCNs) cause serious crop losses in potato. They can also infect other solanaceous crops and weeds. Symptoms on potato include stunting, yellowing, and wilting of leaves as well as a reduced root system. Damage to the crop varies from small patches of poor growing plants to complete crop failure. Diseased plants first occur in isolated patches and these become larger with each new crop. In light infestations, plants may show no above ground symptoms, but yield can be reduced. Light infestations can reduce tuber size, whereas heavy infestations reduce both number and size of tubers.

The nematodes are not greatly influenced by soil type and temperature. They can survive in soil, in the absence of a host, for up to 20 years as cysts containing viable eggs. Spread occurs via infected soil, water, wind, or on plant material. It takes several years from introduction into a paddock before PCN numbers reach a detectable level. Disease management includes exclusion, crop rotation with non-host species, and use of crop cultivars resistant to specific PCN races. Both PCNs have been included on the alert list of the European Plant Protection Organisation (EPPO).

Maps
Iran:
<http://www.lib.utexas.edu/maps/middle_east_and_asia/iran_pol01.jpg>  and <http://healthmap.org/r/00cZ>  Worldwide distribution of golden PCN (July 2008):
<http://www.eppo.org/QUARANTINE/nematodes/Globodera_rostochiensis/HETDRO_map.htm> 

Worldwide distribution of pale PCN (July 2008):
<http://www.eppo.org/QUARANTINE/nematodes/Globodera_pallida/HETDPA_map.htm>
Pictures
Symptoms of golden nematode on potato plants:
<http://www.dpi.vic.gov.au/CA25677D007DC87D/LUbyDesc/Ag0572a/$File/Ag0572a.jpg>
and
<http://www.nysaes.cornell.edu/ent/bcconf/talks/images/brodie2.gif>
_G. rostochiensis_:
<http://plpnemweb.ucdavis.edu/Nemaplex/images/G053s1J2.jpg>
Golden and pale PCN cysts:
<http://www.eppo.org/QUARANTINE/nematodes/Globodera_pallida/HETDSP_images.htm>
Links
Information on _G. rostochiensis_:
<http://www.dpi.vic.gov.au/dpi/nreninf.nsf/childdocs/-71E8091F577D52D24A2568B30004F3B2- 07E8C65C31CFC12CCA256BC800029303-4C9C6833948D4DF54A256DEA00274836-386AFCFE1CD9F10ECA256BCF000BBFE4?open>, 

<http://nematode.unl.edu/pest6.htm>, and <http://plpnemweb.ucdavis.edu/nemaplex/Taxadata/G053s2.htm>
Information on _G. pallida_:
<http://nematode.unl.edu/pest5.htm> and
<http://plpnemweb.ucdavis.edu/nemaplex/taxadata/G053S1.HTM>
Data sheets on both potato cyst nematodes:
<http://www.dpi.qld.gov.au/cps/rde/dpi/hs.xsl/4790_12368_ENA_HTML.htm>,
<http://www.eppo.org/QUARANTINE/nematodes/Globodera_pallida/HETDSP_ds.pdf>,
<http://plpnemweb.ucdavis.edu/nemaplex/Taxadata/G053S2.HTM> and <http://www.inspection.gc.ca/english/plaveg/pestrava/gloros/tech/glorose.shtml> 

EPPO A2 alert list:
<http://www.eppo.org/QUARANTINE/listA2.htm>.  - Mod.DHA]