A ProMED-mail post
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Date: Fri 11 Dec 2020
Source: En24 [edited]
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An unknown variant of potato wart was discovered in Stadskanaal [Groningen province]. According to the NVWA [Netherlands Food and Consumer Product Safety Authority], the new variant may have consequences for the control of wart disease in the northeast of the Netherlands. It is still unclear whether potato varieties with good resistance to the known forms of wart disease are also resistant to the variant. The NVWA is investigating the origin of the infection and the possibilities for a targeted approach.
According to Dirk Jan Beuling of LTO [Netherlands Agricultural and Horticultural Association], the discovery of the new variant is "disappointing. It was found in 2 plots during a check for brown rot."
A similar situation occurred in 2003, when an unknown variant of wart disease was discovered. Collaboration with the sector provided insight into the resistance of important potato varieties. The NVWA wants to do this again. Research is also being used to find which potato varieties are at risk. According to Beuling, it is difficult to say how things will develop. "If the infection has spread and there are no resistant varieties, new varieties must be found. But that can take years."
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Communicated by: ProMED-mail <promed@promedmail.org>
[Potato wart disease (PW) is caused by the fungus _Synchytrium endobioticum_, which is considered one of the most important pathogens of the crop. It is endemic in Europe and has also been reported from a number of locations in the Americas, Australasia and Africa. The pathogen can also affect tomato and some solanaceous weeds.
On infected tubers, "eyes" develop into characteristic warty, cauliflower-like swellings. If infected early, the whole tuber can be replaced by a warty proliferation. Warts darken with age and eventually rot and disintegrate. Plant vigour is reduced, both quantity and quality of harvested tubers are severely affected.
Diagnosis requires laboratory confirmation, as similar symptoms can be caused by other pathogens. The fungus goes through cycles of proliferation and re-infection as long as cool, wet conditions prevail and is, therefore, less damaging in warm, light, well drained soils.
The disease is spread with soil (for example on farm tools), by infected seed tubers and also in manure from animals fed on infected potatoes. The fungus can survive in soil for up to 40 years in the absence of a host. Disease management is based on pathogen exclusion by quarantine regulations and the control of local pathogen spread.
Use of certified clean seed tubers is crucial, contaminated seed lines pose major risks of losses both in yield and international trade.
Fungicides are ineffective, but some experimental fumigation treatments have been shown to kill resting sporangia (see link below).
There are several pathotypes defined by their virulence on different host cultivars. Potato varieties resistant to a number of them have been developed, but new pathogen strains are emerging, compromising the efficacy of host plant resistance.
It is unclear from the report above what diagnostic methods the claim of the outbreak to be due to a 'new strain' of the pathogen is based on. A wart outbreak of unknown origin was also reported recently from Germany (ProMED-mail post https://url.emailprotection.link/?b7TedUeNwSRDQGvunbpe9kCHD0XPa7Jm7d1JpHdONdTq5ujDg-pqInavcOexkFNeWYWjdzHjjW_aQXL-7FRrvdoO2yts8nkgMMKpBeKa-6mgwfLYlCDlgb94kQ3UATqZi)
from Lower Saxony which borders the Dutch Groningen province. It would appear prudent to investigate whether the two outbreaks are in any way related.
Brown rot (also called bacterial wilt) of potato, also mentioned above, is caused by _Ralstonia solanacearum_ race 3 (biovar 2, adapted to cooler temperatures) or race 1 (prevalent in warmer areas). For more information, see previous ProMED-mail posts in the archives.
Maps
Netherlands:
<https://url.emailprotection.link/?bwpkJQ79T4jmdoh8QGreCEPepP71mwmcEMmZdLCBN3Nt35hHFYm4F9q_8QWz0IUr0i74fr6goaxx0LGuW0nAc0UL1tzjA1DlzNgQk1dD5QGtNSndLZFJ3DpZG24OjZknV>
(with provinces)
Europe, overview:
<https://url.emailprotection.link/?bJpjrAQvbo_U19gfVXS2T6Yw1Lg-KmMA_jymow4eTwY7KOuAxQMRDRMkRWF25Rso5PcwVwXzDIn74mPoIvKA2o_gv75PyIqNu4qT5jw4ZGRotj3EcIBpibKjkSzKmjzky>
Pictures
Potato wart symptoms:
<https://url.emailprotection.link/?bYairwTxPNFYi3pnwGsIWBQ32teYK1MpkhD4RKWDxrcSKS-Wbx1KS9RiBnf5ewClr1om2lU6F_y7KUBjmHtd5bBPZyHMytpGfn7QaWTAz4lWOXFF5vSQNkAbjZ5DS-Bf-pjHHS028XMn9bAyJarI6B1eYf3mG6rKCkYZFYRZKJRM~>,
<https://url.emailprotection.link/?bp0QjF7pupW49lXmqIzBlvyDwqEHY3R44lMUdsk5FqYvGi-mj5MLAa1UDWA0JvUNtPD-s51jPaBEx4FrR65mQNUqVhNF5HpHoM1b-c3aCkaTiI1n-7m7lqFywNQt6UZxI> and <https://url.emailprotection.link/?buXXkVwP-QojxETv8FKXhq7H-9EC4CGLu-Ljc5ggPizYe1reZkGck25vn6SYvW7jfF17maq-ZSkZRGFdxKfHHFZ3G7ZwkRl8f5T_DZW1wJ2J2pGiGKSNqUfBNJR9QM94r>
_S. endobioticum_, microscopy:
<https://url.emailprotection.link/?bQJvncgASH4QVsR77P9cHc0-u2h1kyF304-QG4b0c9Kv_q6XT5MwnAxygV_Hhu0DGYChlYfsfsbmvjIoXXMfuLhF2oilrG-q7WCpKPUW-UWXVSf50ameNWDh2SKHtsoAz>
Links
Additional news stoies:
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and
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(original story, in Dutch)
Information on potato wart disease:
<https://url.emailprotection.link/?bHLZnBwoj0kpr-xcxtA3yrkfOjG7XgisxHyiWESc2RqknOrGHNYU7qk0HXN7oEjbvCCgMc-qa_EUBoyZPLXsfLw~~> (with country information), <https://url.emailprotection.link/?bcRoRCTBt733KxWzJznXB4TxozMM3CjViD7kNAS_atb386XBGWLCjToPE0-M7y-if-RnX3uWU1aT2smAUZ11Y3XquIt6QDa6vxiOINXvCLojfEjjLnvQZQGsPkDPGv87u>,
<https://url.emailprotection.link/?bjfx2SheEa0pqfLogvxk4Db-cfQ2SHPbnpbfe14w7feg-yyi3Ct5Ys2zRXlM-rhYU1WOVETeRITDD0apaqIinPVL-5O07e4Ou82baMtMQeOxniin41e8qdJMwPox7Jv_m>,
<https://url.emailprotection.link/?bFPm_XLXUSOTsb8I9JUdNx4vDRgUNTYTal0xHs1l31AVLAZPWZ0tM2HvU9lVHFK51FxzE6vo2pTsVsENpnNG_WDLn9CHVg2pUY1iFsek0nKA2bFIOV20PSXzK6wRq73Yq>,
<https://url.emailprotection.link/?bza-aJOhKxJuH0bAWNpPsU_YNoIgMr-w8r4VEN_JDRAY0PCYfneq0TssvU6Fa7DX1Y1Vc5kTVWn76-4zCMiCkXcqif3rTZFFqGh15AzXHkOAgQY-yF7dCThPEsCYs02X7> and <https://url.emailprotection.link/?b_0q0HfjFidJJ_Lzg2_t190fpUoTgzGVgACM3548itBsV8AwHcDt-BJxtl5YjPT2MoUzNu0lykTnyBnxnM19m4vqdkbd77A1uetzxOoZJWOTr_x8yxgeUR6VcFs5Xhhu3>
Potato wart life cycle:
<https://url.emailprotection.link/?biXrcabMmMVbuYJ33ZxRDOOHn8yzNY255XlWCxlj-QZ2LEEmBeWw5p8TPONkpl3v4C0TyhK6T-OsqsZKJwUbpeF7doHBaV4gOQ6n4uScSuWO4BIVlEYngsZp7Z7ET-yl5>
_S. endobioticum_ taxonomy:
<https://url.emailprotection.link/?b1Q_tZlsNsEMwUDGd0sClUenRThESFEhbZDO3W6M3-AP0aJxOoUsr_s8nvN_GRXUeqxkgM4vaLw5qy74v4swWeHCJ92R1K6ud2tCjDt7DrE-NYpGk9FIBEIc0x6jYQ-F0>
NVWA:
<https://url.emailprotection.link/?bjAO09pCgWVuB28niusEuRbb8LoZPlFpLL_lchoj-JNbVITaSblvjxKTXOrqzwtAV9pqeMSV-UbmU679LGPIxrQ~~>
LTO:
<https://url.emailprotection.link/?byKWgYzX0cwcFgTyTgl1cigfgJ3TopJPr7JISAYQA9ZhivU6jR6AoFUlPXoNcLX6OkKgM3Gob_CiaN9TsEGmbWg~~>
- Mod.DHA]
[See Also:
Wart disease, potato - Canada: (PE)
https://url.emailprotection.link/?b3KPgL_RLfkHP8YkbD1rGT0pwO-QTV7Ih8uOZpEtTEONMXCitN_mJez6xK1aqmVOGkUMOkuXEvbrpFZPQIMOyfobYRp4_bTYz5IX6il2VFTZlXDUd6_bYPGQj2lgnlyln
Wart disease, potato - Germany: (NI)
https://url.emailprotection.link/?b7TedUeNwSRDQGvunbpe9kCHD0XPa7Jm7d1JpHdONdTq5ujDg-pqInavcOexkFNeWYWjdzHjjW_aQXL-7FRrvdoO2yts8nkgMMKpBeKa-6mgwfLYlCDlgb94kQ3UATqZi
2019
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Wart disease, potato - Georgia: pathotype https://url.emailprotection.link/?byGHvveR1xfp6D8KrZeunEm66qZVOENXhrrezwJG3b-QpDQjMyxtTGWKM1KyyDD1kERKirXyBwQMN1nE70ZIBlGWKHIDK0lFjsSJEs_7GtTaeynOBf9zOGh_om16f02Xb
2018
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Wart disease, potato - Ukraine: (IF,CV)
https://url.emailprotection.link/?bWrUPohFmU-DWjw80ca_lFS261Z_2Zc4CbB1iuvCPcSo2LaRt88kqXNdOTMT9TRVtTnu-0ZLc7CcvilI5z_na0dvMSisXXn_xjcdEWbF1KWCEcFhi3YaUxI5vJ8KohbrL
Wart disease, potato - Sweden, Germany
https://url.emailprotection.link/?bVSJaMZXfMCVOyRzFKUsi4RcSq-oLKDD6Y1oRNssSYvrVGrEB5VXB2ao-jOgXFrz6025FkoB0rGu4GNSh4uwUF-yw7p-uRIPk7SHeT5c8TPfO93GvsPHNweLdmCpdt9KQ
Wart & brown rot, potato - Georgia, Russia: interceptions https://url.emailprotection.link/?buXAEsBBTYbAdMctDVzSlb9GJd-G7pG0DpTQi-f3Ys_vUYM_rCY2MKxi_IAgQE4FeTaxhBQWGJrnKTCSkA4EywF6nSJ2beSsPWwmhlcBDP9IVaZJUreUhsASDU0QxvLAM
2014
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Wart disease, potato - Denmark: (MJ)
https://url.emailprotection.link/?bik4LsmwtNNdWOILXNJTFqTPxSDKNvz1Myc4Q3GWqHdCElH_2CfAJxEZUNeYMBgbx554Mj74LqX6R5Mmp0fI1YuCG9JEHdKCrPAHL87zD7puwSV4dYK8L3wRnqu_PtDim
Wart disease, potato - Canada: (PE)
https://url.emailprotection.link/?bnMPZTE1es0M0cC2trUnksBqkMGC-dRgiV8l9457lX_pY4XNvQ5Y6pHyQfei02UaBcoZjPDPQvyJulamEhqJZN-BHrHEu0iPdb2K0f4pi95Nub4QtlWs073CGbwMahrh_
2012
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Wart disease, potato - New Zealand: (SO)
https://url.emailprotection.link/?bAZE5wm6u5XWNRB_E5KgsNslbDDyKYEuhr7hgHOCt8sFoxSnWu0OI03mcUgddJt24J1TTGxuUfrPZZVrqWW_xo8fI0jyJl_FCtwyuOgyun4pFhCpO6WE79bjtu4IwVfz0
Wart disease, potato - UK: (N Ireland) eradication https://url.emailprotection.link/?bkes7jlsxEU1wpFUiRSL5R3HPNKnrGmjd_cncjVFJWz44CJrOdSzJGQPbJQ3tj2uSPS30s7woHk8Y_R_pkcwLJlVi5IdUbKune5fqCn9HigDkzY1M9Fmni9JxRBdAYFgB
2009
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Wart disease, potato - India: (WB)
https://url.emailprotection.link/?bgls2lG8Pmqqj2wzYboGFSajE6rYjD-c0B3tFRtZfPTBPNyEqg5SHAIEJHQok84_DoGvDERcLj3NCo74GFdzdcj98uwQL2NBlBzzMa13mjZzyo4fDfLFvpdVFx2qlmH6p
2007
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Potato wart disease - Canada: (PEI), spread https://url.emailprotection.link/?bgls2lG8Pmqqj2wzYboGFSajE6rYjD-c0B3tFRtZfPTANk-P3BZMIYrrmDq9E_gXJqljCXCeHa-J58oJJ1mEwwrlcRZmqowWKqV96Fd2WIQ-8VAaJsYtGRwEwnUnCsCux
Pale cyst nematode & wart, potato - USA
https://url.emailprotection.link/?bYbfmdTaOd8bwbUcwAf29opZaoj4Gq91EEyvzWjGmqu3HngpIyqH-2Qg2RMIRTDXQ5RzR-19EmiOz_HNFWl25msWLAvh1kfZw2JDI45S_m9tJz3OmunEP-IbXIL7UuWaO
and older items in the archives]