PM 7/28 (2) Synchytrium endobioticum

Specific scope

This Standard describes a diagnostic protocol for Synchytrium endobioticum. 1 This Standard should be used in conjunction with PM 7/76 Use of EPPO diagnostic protocols.

Specific approval and amendment

Approved in 2003‐09. Revision approved in 2017‐06.     

PM 3/59 (3) Synchytrium endobioticum: descheduling of previously infested plots

Specific scope

This Standard describes a procedure for descheduling plots previously infested by Synchytrium endobioticum.

Specific approval and amendment

First approved in 1999‐09. Revisions approved in 2003‐09 and in 2017‐09.     

Pathotypes of Synchytrium endobioticum in Germany

Results are given of a survey on the occurrence of pathotypes (races) of Synchytrium endobioticum (potato wart) in both parts of re-unified Germany. An assortment of six differential cultivars appears to be sufficient to distinguish between the seven presently important German wart pathotypes. A total of ten pathotypes was recorded. Two West and two East German pathotypes seem to be identical, based on the results obtained with presently available cultivars. In contrast to pathotype 1 (common race) which prior to 1945 was distributed over the whole German territory, the 'new' pathotypes seem to prefer the central and south German mountain areas.     

Detection methods for Synchytrium endobioticum1

Methods commonly used to determine the level of infestation of soil with zoosporangia of Synchytrium endobioticum are often laborious and call for complex equipment and costly and toxic chemicals. After comparative study of various existing methods, the authors propose a simple method based on centrifugation of soil residues in salt solutions of different density.     

National control measures for Synchytrium endobioticum1

Although Synchytrium endobioticum has been found in almost all potato-growing countries of the EPPO region, it is absent from the great majority of fields. A few plots scattered across the potato-growing areas have been ‘scheduled’ as infested but potatoes are not grown on them. The disease is accordingly hardly ever seen. This is the result of continent-wide multiyear campaign of potato wart control within countries, according to which it is prohibited to grow potatoes on infested plots, and only resistant cultivars may be grown in a safety zone around them. S. endobioticum can persist for several decades in soil, as resting spores, but it is now dying out in plots that have been subject to the control campaign for a sufficiently long period. Procedures are now being agreed for officially ‘descheduling’ such plots.     

Assessment of varietal reactions to potato wart (Synchytrium endobioticum) in Germany

A key for official assessment of potato cultivars for their resistance to Synchytrium endobioticum (potato wart) is presented. The margin between resistant and susceptible reactions is determined solely by the intensity of necrosis. Low numbers of ripe wart sori can be tolerated, if substantial necrosis occurs simultaneously. The key is a combination of the testing procedures of the two former German States and has been officially applied in Germany since 1992.     

Occurrence of potato wart disease (Synchytrium endobioticum) in Bulgaria: identification of pathotype(s) present

Potato wart disease caused by Synchytrium endobioticum was detected for the first time in Bulgaria in 2004. Laboratory tests, pot tests and field tests were carried out to determine which pathotype is present, specifically in Prodanovtsi near the town of Samokov. In addition, potato cultivars were tested for levels of resistance, in order to be used in buffer zones surrounding infested fields. Based on the results obtained in this study, it was found that most probably pathotype 8(F1) is present in Bulgaria. Most of the commercial potato cultivars tested were found to be susceptible to this pathotype. The local cultivars Koral and Bor were resistant, but these are not very important cultivars commercially. The potato cultivars Panda, Désirée and Amorosa were recommended for cultivation in the fields adjacent to infested plots.     

昭通内生集壶菌发生情况及防治策略

通过对发生区调查和历史数据分析,总结昭通内生集壶菌发生原因,根据昭通防治经验,结合国内研究成果,提出加强检疫,清除田间病残体,收集病薯高温处理,发病区进行轮作并全部挖出隔生薯,轮作后种植抗病品种的防治策略。     

The Longevity of Resting Sporangia of Synchytrium endobioticum (Schilb.) Perc. in Soil1)

Resting sporangia of the potato wart disease pathogen Synchytrium endobioticum (Schilb.) Perc. which persist in soil can be extracted from soil by a wet-sieving and chloroform centrifugation method and counted. Soils from the sites of old wart outbreaks have been checked for resting sporangia. Sampling procedures, patterns and errors are being assessed.     

Variability of Synchytrium endobioticum in the Carpathian region of Ukraine1

The appearance of aggressive pathotypes of Synchytrium endobioticum in the Carpathian area of Ukraine is reviewed. An analysis is made of the factors that favoured their appearance in this area. Possibilities for distinguishing the pathotypes by characters other than their behaviour on differential cultivars are considered.     

Differential cultivars for aggressive pathotypes of Synchytrium endobioticum in Ukraine1

The use of a internationally agreed standard differential set of potato cultivars to identify aggressive pathotypes of Synchytrium endobioticum is reviewed. In recent years, many new cultivars and hybrids have been tested in Ukraine for their reaction to the Carpathian pathotypes (11, 13, 18 and 22). Because of the specificity and stability of their reactions, and their availability, some of these potato cultivars are now recommended as part of a new differential set for use in Ukraine, especially with respect to the Carpathian pathotypes.     

Definition and distribution of aggressive pathotypes of Synchytrium endobioticum in Ukraine1

Aggressive pathotypes of Synchytrium endobioticum have been detected in Ukraine since 1963, mainly in the mountainous western part of the country. Potato crops are regularly surveyed to detect possible outbreaks. It has been observed that the aggressive forms attack the above-ground parts of the potato plant, as well as the underground parts, and this can assist detection. Possible foci are investigated by planting a standard replicated test with a susceptible cultivar and a cultivar resistant to the common pathotype. The distribution of S. endobioticum in Ukraine is summarized. Outbreaks are particularly found in potato plots adjoining farm buildings.     

Identification of pathotypes of Synchytrium endobioticum found in infested fields in Turkey

Pathotypes of four isolates of Synchytrium endobioticum collected from the infested areas of Turkey were determined using Glynne–Lemmerzahl and Spieckermann test methods. Two isolates (Ordu 1 and Nevşehir 1) were tested by the Glynne–Lemmerzahl method in Germany. Ordu 1 was assigned as pathotype 1(D1) whereas the other isolate gave different results in 2 years of testing [pathotype 6(O1) or 18(T1)]. Two other isolates (Nevşehir 2 and Nevşehir 3) were tested using the Spieckermann method in Netherlands. Neither of these last two isolates tested were found to belong to the pathotypes known from Western Europe. The isolates Nevşehir 2 and Nevşehir 3 were given a new, unique code: 38 (Nevşehir).