J. Crop Prot. 2020, 9 (2): 347-354______________________________________________________ Short paper Notes on powdery mildew of evergreen spindle Euonymus japonicus in Iran Mehrdad Abbasi1* and Uwe Braun2 1. Department of Botany, Iranian Research Institute of Plant Protection, Agricultural Research Education and Extension Organization (AREEO), Tehran, Iran. 2. Institut für Biologie, Bereich Geobotanik und Botanischer Garten, Martin-Luther-Universität, Herbarium, Neuwerk 21, 06099, Halle (Saale), Germany. Abstract: Since the beginning of the 20th century, several scientific names have been used for the causal agent of powdery mildew on evergreen spindle Euonymus japonicus. The nomenclature of this powdery mildew is reviewed and using Erysiphe euonymicola as current name for the species is suggested. Information on the history of occurrence, natural host range and distribution of E. japonicus powdery mildew in Iran is provided. Morphological differences between E. euonymicola and E. euonymi, a powdery mildew on other species of Euonymus in Europe is discussed. Keywords: Nomenclature, Erysiphales, Fungi Introduction12 phytopathological publications. The first observation of this powdery mildew in North Evergreen spindle, Euonymus japonicus L. f. America dates from September 1897, based on (Celastraceae) is an ornamental shrub with a specimen collected by Magnus in San diverse cultivars, cultivated in many countries Francisco (Viennot-Bourgin, 1966). Nearly all across the world. This shrub is commonly reports of the powdery mildew of evergreen infected by a powdery mildew species almost spindle from the 20th century, as well as all Downloaded from jcp.modares.ac.ir at 8:21 IRST on Monday September 27th 2021 worldwide. Arcangeli (1900) described this specimens deposited in herbaria, refer to the fungus as Oidium leucoconium f. euonymi- asexual morph (anamorph), i.e., the sexual japonici (not as variety as usually cited in morph (telemorph) was missing. Generations of literature), based on collections from Florence mycologists and phytopathologists have tried to and Livorno. Since 1900, some mycologists discover the teleomorph (chasmothecia) of this have recorded its occurrence in other European fungus in nature, but failed. Hara (1921, 1922) countries. The first observation in England was assigned Oidium leucoconium var. euonymi- made by Salmon (1905) under the name Oidium japonici to Microsphaera and Uncinula, euonymi-japonici (Arcang.) Sacc. Since that respectively, but just based on the asexual time powdery mildew of evergreen spindle was morph. Viennot-Bourgin (1966) was the first usually referred to as O. euonymi-japonici, and mycologist who observed ascomata on this name was widely used in mycological and evergreen spindle powdery mildew on specimens collected in France and former Yugoslavia. However, he published the name Handling Editor: Rasoul Zare "Microsphaera euonymi-japonici" without __________________________ * Latin description (Viennot Bourgin, 1966) [= Corresponding author: [email protected] Received: 05 January 2020, Accepted: 20 April 2020 nom. inval., Art. 39.1 (Shenzhen Code)]. Later Published online: 04 May 2020 347 Powdery mildew of E. japonicus in Iran ______________________________________________ J. Crop Prot. he validated this name (Viennot-Bourgin, Evergreen spindle is cultivated in Iran for 1968), which was widely used since then (e.g., nearly a century and infected by powdery Braun, 1987, 1995). Microsphaera euonymi- mildew almost everywhere. An overview of japonici was the accepted name for evergreen reports of powdery mildew on evergreen euonymus powdery mildew till Braun and spindle in Iran is given in Table 1. The first Takamatsu (2000) considered the genus documented Iranian collection was reported Microsphaera a synonym for Erysiphe, based 70 years ago as Oidium euonymi-japonici. In on results of phylogenetic analyses, and addition to this name, Microsphaera proposed the combination “Erysiphe euonymi- euonymi-japonici and Erysiphe euonymi- japonici (Vienn.-Bourg.) U. Braun & S. japonici have also been used to name the Takam.” [since 2012 (Melbourne Code), causal agent of evergreen spindle powdery Microsphaera euonymi-japonici Vienn.-Bourg., mildew in Iran. Recently, the powdery 1968, is an illegitimate name (homonym of M. mildews (Erysiphales) of Iran have been euonymi-japonici (Arcang.) Hara, 1921), so that keyed out by Abbasi and Salahi Ardakani the former combination Erysiphe euonymi- (2017). They considered E. euonymicola as japonici has to be treated as new name only current name for E. japonicus powdery ascribed to U. Braun and S. Takamatsu]. Braun mildew (see Table 1). and Cook (2012) discussed the nomenclature The fungal nomenclature has been and taxonomy of evergreen spindle powdery significantly affected by the Melbourne Code mildew and concluded that the connection (McNeill et al., 2012). Therefore, a detailed between E. euonymi-japonici and the common discussion of the history and nomenclature of anamorph on evergreen euonymus has never evergreen spindle powdery mildew is been proven and that the ascomata described by necessary in the context of a survey on host Viennot-Bourgin (1968) do not pertain to range and occurrence of this species in Iran. Oidium euonymi-japonici. The sexual morph of Using Iranian specimens, comparative E. euonymi-japonici has never been re-collected morphology between E. japonicus powdery and its type specimen could not be traced and is mildew and Erysiphe euonymi DC., common probably not preserved. Therefore, Braun and powdery mildew on other Euonymus species in Cook (2012) rejected this name and put it into a Europe, is also provided. list of doubtful and excluded taxa. Finally, Braun (in Braun and Cook, 2012) introduced Materials and Methods Downloaded from jcp.modares.ac.ir at 8:21 IRST on Monday September 27th 2021 the new species Erysiphe euonymicola on the basis of new anamorph and teleomorph material Numerous herbarium specimens and recently collected on evergreen spindle in France as collected material were used for this study. causal agent of powdery mildew on E. Morphological examination of the specimens japonicus (Braun and Cook, 2012). The fruiting was conducted using procedures described by bodies found on E. japonicus, embedded in Abbasi et al. (2019). Anamorphic and mycelial patches and associated with the teleomorphic states were observed separately anamorph of evergreen spindle powdery under BH2 Olympus light-microscope, using mildew, were morphologically very similar to lactic acid in glycerol mounting medium chasmothecia of Erysiphe alphitoides (Griff. & (Abbasi, 2013). All photomicrographs taken by Maubl.) U. Braun & S. Takam. and E. Dino-Eye Eyepiece Camera using DinoCapture quercicola S. Takam. & U. Braun, which makes 2.0 software (AnMo Electronics Corporation, sense since evergreen spindle powdery mildew Taiwan). In each accession, 30 chasmothecia, was phylogenetically very close to the latter conidia, and conidiophores were measured. two species, but distinct on species level Studied materials have been deposited at IRAN (Limkaisan et al., 2006; Takamatsu et al., (Iranian Research Institute of Plant Protection) 2007). herbarium. 348 Abbasi and Braun _________________________________________________ J. Crop Prot. (2020) Vol. 9 (2) Table 1 Overview on reports of Euonymus japonicus powdery mildew in Iran. Published name Locality Reference Oidium euonymi-japonici Ramsar Esfandiari, 1948 Oidium euonymi-japonici Iran Steyaert, 1953 Oidium euonymi-japonici Northern Iran Khabiri, 1956 Oidium euonymi-japonici Tonekabon Eskandari, 1964 Microsphaera euonymi-japonici Tehran, Karaj Nader-Nejad, 1966 Oidium euonymi-japonici Iran Scharif and Ershad, 1966 Oidium euonymi-japonici Esfahan Daftari and Behdad, 1968 Microsphaera euonymi-japonici Lahijan Viennot-Bourgin et al., 1969 Oidium euonymi-japonici Tehran, Karaj Mohammadi-Doustdar, 1969* Microsphaera euonymi-japonici Iran Ershad, 1971 Microsphaera euonymi-japonici Iran Amano, 1986 Oidium euonymi-japonici Iran Amano, 1986 Oidium euonymi-japonici Iran Behdad, 1988 Erysiphe euonymi-japonici Yazd Samadi et al., 2010 Erysiphe euonymicola Iran Abbasi and Salahi Ardakani, 2017 *The host mentioned as Buxus sempervirens. Results and Discussion Uruguayensis, Plantes Avasculares: 33, 1933, isonym]. The nomenclature of the powdery mildew on E. ≡ Uncinula euonymi-japonici (Arcang.) Hara, japonicus is extremely complicated and has Dendropathology [Jubyo-gaku Kakuron]: 22, changed based on the Melbourne Code. In any 1922. case, the correct name for this fungus is E. ≡ Pseudoidium euonymi-japonici (Arcang.) euonymicola described by Braun in Braun and U. Braun & R. T. A. Cook, Taxonomic Cook (2012). Its synonymy can be summarized Manual of the Erysiphales (Powdery as follows: Mildews): 461, 2012. Downloaded from jcp.modares.ac.ir at 8:21 IRST on Monday September 27th 2021 Erysiphe euonymicola U. Braun, in Braun & Misapplied name: Microsphaera euonymi- Cook, Taxonomic Manual of the Erysiphales japonici Viennot-Bourgin, Bull. Trimestriel (Powdery Mildews): 461, 2012. Soc. Mycol. France 84(1): 118, 1968, nom. = Oidium leucoconium f. euonymi-japonici illeg. (ICN, Art. 53.1), non Microsphaera Arcang. (as “Evonymi japonici”), Atti Soc. euonymi-japonici (Arcang.) Hara, 1923. Tosc. Sci. Nat. Pisa, Processi Verbali 12: 109, ≡ Erysiphe euonymi-japonici U. Braun & S. [“1899-1901”] 1900 [non Erysiphe euonymi- Takam. [as (Viennot-Bourgin) U. Braun & S. japonici U. Braun & S. Takam., 2000]. Takam.], Schlechtendalia 4: