| Legend |
|---|
| Justification for qualification based on EPPO PM 4 Standards |
| Justification for disqualification |
| Additional or non-conclusive information |
| Standard text |
NAME OF THE ORGANISM: Roesleria subterranea {Sclerophora pallida} (ROERSU)
GENERAL INFORMATION ON THE PEST
Name as submitted in the project specification (if different):
Sclerophora pallida (Roesleria pallida)
Pest category:
Fungi
1- Identity of the pest/Level of taxonomic listing:
Is the organism clearly a single taxonomic entity and can it be adequately distinguished from other entities of the same rank?
Yes
Is the pest defined at the species level or lower?:
Yes
Can listing of the pest at a taxonomic level higher than species be supported by scientific reasons or can species be identified within the taxonomic rank which are the (main) pests of concern?
- Not relevant: Fruits (including hops) sector
If necessary, please list the species:
-
Is it justified that the pest is listed at a taxonomic rank below species level?
Not relevant
Conclusion:
- Null: Fruits (including hops) sector
Justification (if necessary):
Roesleria subterranea is morphologically very similar to the lichen, Sclerophora pallida (Pers.) Y.J. Yao & Spooner (synonym Roesleria pallida (Pers.) Sacc.), and this has led to confusion. The name R. pallida had been misused frequently to refer to R. subterranea (as Roesleria hypogaea; Beckwith 1924). Dennis (1978) considered R. pallida as a synonym of R. hypogaea. However, the name Roesleria pallida is not applicable to the grape root parasite (Redhead 1984, Beckwith 1924), as it is based on the lichen S. pallida (previously known as Calicium pallidum Pers.). This confusion has been comprehensively discussed by Redhead (1984) and Yao and Spooner (1999) (Cited from Edwards et al. 2015). R. pallida linked to replant disease in apple and grapevine, mentioned by Veghelyi (1984, 1987) and Molnar et al. (2003), are now attributed to Roesleria subterranae (Edwards et al. 2015).
The Fruit SEWG recommended that the summary sheet should address Roesleria subterranea.
The Fruit SEWG recommended that the summary sheet should address Roesleria subterranea.
2 – Status in the EU:
Is this pest already a quarantine pest for the whole EU?
No
Presence in the EU:
Yes
List of countries (EPPO Global Database):
-
Conclusion:
Candidate
Justification (if necessary):
Due to confusion in taxonomy it is unclear which reference are referring to Sclerophora pallida and which refer to Roesleria subterranea.
Roesleria subterranea has been reported in Austria (Kirchmair et al., 2008), France (Delatour & Guillaumin, 1985, in Neuhauser et al., 2011), Germany (Kirchmair et al., 2008), Hungary (Veghelyi, 1987; in Neuhauser et al., 2011), Italy (Kirchmair et al., 2008), the Netherlands (Kirchmair et al., 2008), but due to the taxonomic confusion, this list is probably not complete.
Roesleria subterranea has been reported in Austria (Kirchmair et al., 2008), France (Delatour & Guillaumin, 1985, in Neuhauser et al., 2011), Germany (Kirchmair et al., 2008), Hungary (Veghelyi, 1987; in Neuhauser et al., 2011), Italy (Kirchmair et al., 2008), the Netherlands (Kirchmair et al., 2008), but due to the taxonomic confusion, this list is probably not complete.
HOST PLANT N°1: Pyrus (1PYUG) for the Fruits (including hops) sector.
Origin of the listing:
Commission Implementing Directive (EU) 2014/98/EU and Commission Implementing Regulation (EU) 2019/2072
Plants for planting:
Plants intended for planting
3 - Is the pest already listed in a PM4 standard on the concerned host plant?
Yes
Conclusion:
Evaluation continues
Justification (if necessary):
Inspection for ' Roesleria pallida' recommended in EPPO Standard PM 4-27 Pathogen-tested material of Malus, Pyrus and Cydonia. However, when responding to the questionnaire, NL and PL supported deregulation because of pathway and economic impact. Evaluation continues for these two criteria.
4 - Are the listed plants for planting the main* pathway for the "pest/host/intended use" combination? (*: significant compared to others):
No
Conclusion:
Not candidate
Justification:
Recorded host plants genera for Roesleria subterranea are: Coryllus (hazelnut), Cydonia (quince), Juglans (walnut), Malus (apple), Paliurus, Populus (aspen), Prunus (almond, apricot, plum, peach, cherry, Mahaleb cherry), Pyrus (pear), Rosa (rose), Rubus (blackberry), Salix (willow), Tilia (lime, basswood, linden) and Vitis (grapevine) (Beckwith, 1924; Veghelyi, 1987, 1989; Gärtel 1988 cited in Edwards et al., 2015).
Roesleria subterranea is a soilborne facultative pathogen that can exist as a saprobe on dead material in the soil for many years (Höfer 1992, cited in Edwards et al., 2015). This fungus used to be considered of minor importance as it is difficult to detect and easily confused with the morphologically similar lichen, Sclerophora pallida. Since it is often associated with other root pests such as phylloxera, nematodes and soilborne pathogenic fungi, e.g. Cylindrocarpon species, it was dismissed as a weak secondary invader (Edwards et al., 2015).
During the past decennia, it has become apparent that R. subterranea can be a serious primary pathogen, and can cause death of a variety of fruit trees (Veghelyi, 1987) and grapevines (Miles & Schilder, 2009; Höfer 1992) within 2 to 5 years of infection (Edward et al., 2015). The disease is particularly severe on heavy, wet soils in cool climates with soil temperatures around 15–20°C. However, the fungus is able to tolerate sandy soils, growing at temperatures ranging from -3°C to 35°C, in pH ranges from 2.5 to 8, and with soil moisture ranging from 10–80% water holding capacity of soils (Höfer 1992 in Neuhauser et al 2011).
Roesleria subterranea forms ascomata consist of ‘mazaedia’ (i.e. an ascomata in which the asci walls disintegrate leaving a powdery mass of ascospores at maturity) with paraphyses covering the disc of apothecia (Edwards et al., 2015). The small ascomata of R. subterranea are formed on roots or dead wood 0.05–1.5 m belowground and only rarely above ground (Neuhauser et al., 2011).
Ascospores are not discharged actively, but disperse passively by soil water, soil fauna and movement of infected plant material, contaminated soil, or contaminated machinery (Edwards et al., 2015).
[In the responses to the questionnaire, NL considered that Sclerophora pallida is already widespread in nature.]
The Fruit SEWG noted that the pest was generally not present in nurseries, widely present in orchards, and concluded that plants for planting was not a significant pathway.
Roesleria subterranea is a soilborne facultative pathogen that can exist as a saprobe on dead material in the soil for many years (Höfer 1992, cited in Edwards et al., 2015). This fungus used to be considered of minor importance as it is difficult to detect and easily confused with the morphologically similar lichen, Sclerophora pallida. Since it is often associated with other root pests such as phylloxera, nematodes and soilborne pathogenic fungi, e.g. Cylindrocarpon species, it was dismissed as a weak secondary invader (Edwards et al., 2015).
During the past decennia, it has become apparent that R. subterranea can be a serious primary pathogen, and can cause death of a variety of fruit trees (Veghelyi, 1987) and grapevines (Miles & Schilder, 2009; Höfer 1992) within 2 to 5 years of infection (Edward et al., 2015). The disease is particularly severe on heavy, wet soils in cool climates with soil temperatures around 15–20°C. However, the fungus is able to tolerate sandy soils, growing at temperatures ranging from -3°C to 35°C, in pH ranges from 2.5 to 8, and with soil moisture ranging from 10–80% water holding capacity of soils (Höfer 1992 in Neuhauser et al 2011).
Roesleria subterranea forms ascomata consist of ‘mazaedia’ (i.e. an ascomata in which the asci walls disintegrate leaving a powdery mass of ascospores at maturity) with paraphyses covering the disc of apothecia (Edwards et al., 2015). The small ascomata of R. subterranea are formed on roots or dead wood 0.05–1.5 m belowground and only rarely above ground (Neuhauser et al., 2011).
Ascospores are not discharged actively, but disperse passively by soil water, soil fauna and movement of infected plant material, contaminated soil, or contaminated machinery (Edwards et al., 2015).
[In the responses to the questionnaire, NL considered that Sclerophora pallida is already widespread in nature.]
The Fruit SEWG noted that the pest was generally not present in nurseries, widely present in orchards, and concluded that plants for planting was not a significant pathway.
5 - Economic impact:
Are there documented reports of any economic impact on the host?
Justification:
Apart from the extensive research undertaken by Veghelyi on replant diseases and early death of fruit trees in Hungary (Veghelyi 1985a, 1985b, 1985c, 1986, 1987, 1989, 1994, Molnar et al. 2003), there is very little published information on the effects of R. subterranea on hosts other than grapevine (Edwards et al., 2015).
For fruit trees, as for grapevines, aboveground symptoms merely reflect the root damage and are not specific. Examination of the roots for rotting and the presence of mazaedia is required to diagnose the disease. Veghelyi (1986) reported that infected roots have very few root hairs compared to healthy roots. Losses are mainly concerned with replant disease (i.e. the inability to establish new plantings into land that was previously planted with the same fruit tree species) and premature death of infected planting material both in the nursery and in the orchard (cited from Edwards et al., 2015).
[In the responses to the questionnaire, NL considered that Sclerophora pallida is infecting only dead wood and old trees. NL and PL considered that the pest was not causing any damage in orchard.]
For fruit trees, as for grapevines, aboveground symptoms merely reflect the root damage and are not specific. Examination of the roots for rotting and the presence of mazaedia is required to diagnose the disease. Veghelyi (1986) reported that infected roots have very few root hairs compared to healthy roots. Losses are mainly concerned with replant disease (i.e. the inability to establish new plantings into land that was previously planted with the same fruit tree species) and premature death of infected planting material both in the nursery and in the orchard (cited from Edwards et al., 2015).
[In the responses to the questionnaire, NL considered that Sclerophora pallida is infecting only dead wood and old trees. NL and PL considered that the pest was not causing any damage in orchard.]
What is the likely economic impact of the pest irrespective of its infestation source in the absence of phytosanitary measures? (= official measures)
Is the economic impact due to the presence of the pest on the named host plant for planting, acceptable to the propagation and end user sectors concerned?
Yes
Is there unacceptable economic impact caused to other hosts (or the same host with a different intended use) produced at the same place of production due to the transfer of the pest from the named host plant for planting?
Conclusion:
Justification:
6 - Are there feasible and effective measures available to prevent the presence of the pest on the plants for planting at an incidence above a certain threshold (including zero) to avoid an unacceptable economic impact as regards the relevant host plants?
Conclusion:
Justification:
7- Is the quality of the data sufficient to recommend the pest to be listed as a RNQP?
Conclusion:
Justification:
CONCLUSION ON THE STATUS:
Disqualified: plants for planting is not considered to be a significant pathway.
8 - Tolerance level:
Is there a need to change the Tolerance level:
Yes
Proposed Tolerance levels:
Delisting
9 - Risk management measures:
Is there a need to change the Risk management measure:
Yes
Proposed Risk management measure:
Delisting
REFERENCES:
- Beckwith AM (1924) The life history of the Grape root rot fungus Roesleria hypogaea Thum. et Pass. Journal of Agricultural Research 27, 609-616.
- Delatour PC & Guillaumin JJ (1985). Importance des pourridiés dans les regions tempérées. European Journal of Forest Pathology 15, 258–263
- Dennis RWG (1978) British ascomycetes. (J. Cramer: Vaduz).
- Edwards J, Neuhauser S & Kirchmair M (2015) National Diagnostic Protocol for Roesleria subterranea – NDP35 V1. Subcommittee on Plant Health Diagnostics (reviewer Meadows I). Commonwealth of Australia. https://www.plantbiosecuritydiagnostics.net.au/app/uploads/2018/11/NDP-35-Grape-root-rot-Roesleria-subterranea-V1.pdf
- Gärtel W (1988) Grape root rot. In Compendium of grape diseases (eds Pearson C & Goheen AC). American Phytopathological Society, St Paul, MN, USA. pp. 40-41.
- Höfer M (1992) Untersuchungen über Roesleria hypogaea Thüm. & Pass. als Erreger des Wurzelschimmels der Weinrebe. Dissertation Univ. Gießen
- Kirchmair, M., Neuhauser, S., Buzina, W., & Huber, L. (2008). The taxonomic position of Roesleria subterranea. Mycological research, 112(10), 1210-1219.
- Redhead SA (1984). Roeslerina gen. nov. (Caliciales, Caliciaceae), an ally of Roesleria and Coniocybe. Canadian Journal of Botany 62: 2514–2519.
- Miles TD & Schilder AMC (2009) First report of grape root rot caused by Roesleria subterranea in Michigan. Plant Disease 93, 765.
- Molnar P, Veghelyi K, Balogh I (2003) Grapevine and apple replant disease in Hungary. International Journal of Horticultural Science 9, 29-33.
- Neuhauser S, Huber L & Kirchmair M (2011). Is Roesleria subterranea a primary pathogen or a minor parasite of grapevines? Risk assessment and a diagnostic decision scheme. European Journal of Plant Pathology 130, 503–510. DOI 10.1007/s10658-011-9769-3
- Veghelyi K (1985a) Demonstration of the root fungus Roesleria hypogaea Thum et Pass. which damages the root systems of fruit trees. Kertgazdasag 4, 47-53.
- Veghelyi K (1985b) Temperature requirements determining the damage caused by the root parasite fungi Rosellinia necatrix (Hart.) Berl. and Roesleria hypogaea Thum et Pass. Kertgazdasag 6, 51-58.
- Veghelyi K (1985c) Fungal diseases of the root system of fruit tree grafts. Kertgazdasag 3, 21-27.
- Veghelyi K (1986) Root rot fungi on apricot in Hungary. Acta Horticulturae 192,217-225.
- Veghelyi K (1987) Role of Roesleria pallida (Fries) Sacc. in the early death of fruit trees. Novenyvedelem 23 (9), 405-412.
- Veghelyi K (1989) The isolation and characteristics of Roesleria hypogaea Thum. et Pass. Acta Phytopathologica et Entomologica Hungarica 24 (3-4), 293-299.
- Veghelyi K (1994) Mycorrhizal and root rot fungi of fruit trees. Acta Horticulturae 363, 175-182.
- Yao YJ & Spooner BM (1999) Roesleriaceae, a new family of Ascomycota, and a new species of Roeslerina. Kew Bulletin 54: 683–693.