Jamjan Meeboon

Cystotheca tjibodensis (Erysiphaceae, Ascomycota): rediscovery in Java after 90 years and first finding of anamorph

Cystotheca tjibodensis, formerly known as Lanomyces tjibodensis (Perisporiales), is a fungus found in 1920 in Indonesia. This species, hitherto only known from its type collection, is now regarded as belonging to the Erysiphales. However, molecular data are still required to verify the taxonomic affinity. In March 2011, we rediscovered this fungus at Cibodas Botanical Garden, Java. Detailed characterizations of this tropical powdery mildew are reported in this study based on morphological and molecular examinations. The anamorph of this species that was not found in the type specimen is also reported in this study.

First report of Pseudoidium aff. neolycopersici in Indonesia

Tamarillo was found to be heavily infested with powdery mildew in Bali, February 2012. The cause of the disease, Pseudoidium aff. neolycopersici, was characterised based on the morphology and molecular phylogenetic analysis of the internal transcribed spacer sequence. This is the first report of P. aff. neolycopersici on tamarillo in Indonesia.

Erysiphe havrylenkoana and E. prunastri var. japonica: a new species and a new variety of Erysiphe sect. Uncinula (Erysiphaceae, Ascomycota)

A new species and a new variety of Erysiphe sect. Uncinula are described and illustrated. Erysiphe havrylenkoana is a new species found on Nothofagus alpina and N. obliqua in Argentina, and E. prunastri var. japonica is a new variety collected on Prunus maximowiczii in Japan. Erysiphe havrylenkoana differs from E. nothofagi, E. patagoniaca and E. magellanica in having unique helicoid appendages, brownish from the base to the beginning of helicoid part, spirally twisted at the center and straight or not spiral at the upper part with uncinate to circinate tip. The phylogenetic analyses of rDNA sequences clearly showed that the spiral pattern of helicoid appendages is an important morphological character to delimit species among Nothofagus powdery mildews. Erysiphe prunastri var. japonica is distinct from E. prunastri var. prunastri parasitizing hitherto Prunus species from East-Central Asia to Europe by having mainly eight asci per chasmothecium and smooth, rarely septate appendages.

Notes on powdery mildews (Erysiphales) in Thailand II. Erysiphe species on Adoxaceae Anacardiaceae, Apocynaceae, Araliaceae, Aristolochiaceae, Bixaceae, Brassicaceae, Cleomaceae, Convolvulaceae, Cucurbitaceae and Euphorbiacea

The previous reports on powdery mildews from Thailand revealed some unknown species and also the importance of this area for the diversity, systematics and evolution of powdery mildews. This report provides an additional list consisting of three species of the genus Erysiphe and its asexual morph (Pseudoidium) on various hosts found in Thailand. Morphological descriptions of powdery mildew specimens on 11 plant families and molecular phylogenetic analyses based on ITS rDNA sequences are provided. We report 6 new host records for Erysiphe in the world, viz., Viburnum inopinatum (Adoxaceae), Wrightia arborea (Apocynaceae), Hydrocotyle javanica (Araliaceae), Cleome chelidonii (Cleomaceae), Luffa acutangula (Cucurbitaceae) and Ostodes paniculata (Euphorbiaceae). In addition, 10 new records of Erysiphe found in Thailand are described.

Notes on powdery mildews (Erysiphales) in Thailand III. Erysiphe species on Fabaceae, Fagaceae, Hydrangeaceae and Lamiaceae

This report provides morphological descriptions of powdery mildew specimens found on Fabaceae, Fagaceae, Hydrangeaceae and Lamiaceae and molecular phylogenetic analyses based on ITS rDNA sequences. These include 4 new host records for Erysiphe species in the world, viz., Desmodium triflorum (Fabaceae), Microtoena insuavis (Lamiaceae) and Mucuna bracteata (Fabaceae). Aeschynomene americana var. americana (Fabaceae), Sesbania grandiflora (Fabaceae) and Tamarindus indica (Fabaceae) are new host for Erysiphe trifoliorum s. lat. and Phanera purpurea (Fabaceae) is new host for Erysiphe lespedezae. In addition, 11 records of Erysiphe species new to Thailand were described.

Notes on powdery mildews (Erysiphales) in Thailand V. Golovinomyces

Records of Golovinomyces species new to Thailand are described on the hosts Ageratum conyzoides, Bidens pilosa, Dahlia pinnata, D. × hortensis, Helianthus annuus, Lactuca indica, Laggera crispata, Sonchus oleraceus (Asteraceae), Lygisma inflexum (Asclepiadaceae), Myosotis scopioides (Boraginaceae), Coccinia indica, Coccinia grandis (Cucurbitaceae), Vigna umbellata (Fabaceae), Torenia fournieri (Linderniaceae), Plantago major (Plantaginaceae) and Verbena × hybrida (Verbenaceae). The identifications of the particular Golovinomyces species have been performed by means of morphological examinations supplemented by molecular sequence analyses. On the basis of molecular analyses, the powdery mildew on Ocimum tenuiflorum (Lamiaceae) proved to represent a species of its own, which is referred to as Golovinomyces ocimi comb. nov. The application of Oidium ocimi, the basionym of this combination, is determined by lecto- and epitypification. Lygisma inflexum, Laggera crispata and Vigna umbellata are new host records for Golovinomyces worldwide.

Notes on powdery mildews (Erysiphales) in Thailand VI. Phyllactinia and Leveillula

Nine species of the genus Phyllactinia and one species of Leveillula on various hosts are recorded for Thailand. Morphological descriptions of powdery mildew specimens on hosts belonging to nine plant families and molecular phylogenetic analyses based on ITS and 28S rRNA gene sequences are provided. Phyllactinia mori-macrourae on Morus macroura (Moraceae) is proposed as new species. Phyllactinia mori-macrourae differs from Ph. moricola by having smaller chasmothecia, less chasmothecial appendages, less asci per chasmothecium, and longer ascospores. Ovulariopsis broussonetiae-papyriferae is combined to Phyllactinia broussonetiae-papyriferae. Phyllactinia alangii, Ph. dalbergiae, Phyllactinia cf. ehretiae, Ph. gmelinae, Ph. moricola, Ph. pyri-serotinae, Ph. Terminaliae, and Leveillula taurica are new records for Thailand. Ehretia laevis and S. aculeatissimum are new host records for powdery mildews species worldwide.

Phylogeny and taxonomy of Pseudoidium pedaliacearum

Collections of Pseudoidium pedaliacearum on Sesamum indicum from Japan, Korea, and Nepal have been morphologically examined and subjected to molecular sequence analyses in order to clarify the taxonomic status and phylogenetic affinity of this powdery mildew. Pseudoidium pedaliacearum pertains to the Erysiphe aquilegiae clade, which encompasses several closely allied, morphologically similar powdery mildew species. The close affinity to Erysiphe sedi, Pseudoidium hortensiae (≡ Oidium hortensiae), P. neolycopersici (≡ Oidium neolycopersici), and some other taxa involved in the Erysiphe aquilegiae complex is discussed. The reexamination of P. pedaliacearum and the results of phylogenetic analyses [5′-end of the 28S rRNA gene (including the domains D1 and D2) and internal transcribed spacer (ITS) regions] led to a reassessment of this species and its reallocation to Erysiphe on the basis of the provisions of ICN Art. F.8.

Powdery mildew of Chrysanthemum × morifolium: phylogeny and taxonomy in the context of Golovinomyces species on Asteraceae hosts

ABSTRACT The taxonomic history of the common powdery mildew of Chrysanthemum × morifolium (chrysanthemum, florist’s daisy), originally described in Germany as Oidium chrysanthemi, is discussed. The position of O. chrysanthemi was investigated on the basis of morphological traits and molecular phylogenetic analyses. Based on the results of this study, this species, which is closely related to Golovinomyces artemisae, was reassessed and reallocated to Golovinomyces. The phylogenetic analysis and taxonomic reassessment of the chrysanthemum powdery mildew is supplemented by a morphological description, a summary of its worldwide distribution data, and a brief discussion of the introduction of this fungus to North America. G. chrysanthemi differs from true G. artemisiae in that it has much longer conidiophores, is not constricted at the base, and has much larger and most importantly longer conidia. The close affinity of Golovinomyces to Artemisia and Chrysanthemum species signifies a coevolutionary event between the powdery mildews concerned and their host species in the subtribe Artemisiinae (Asteraceae tribe Anthemideae). This conclusion is fully supported by the current phylogeny and taxonomy of the host plant genera and the coevolution that occurred with the host and pathogen. The following powdery mildew species, which are associated with hosts belonging to the tribe Anthemideae of the Asteraceae, are epitypified: Alphitomorpha depressa β artemisiae (≡ Alphitomorpha artemisiae), Erysiphe artemisiae, and Oidium chrysanthemi. Erysiphe macrocarpa is neotypified. Their sequences were retrieved from the epitype collections and have been added to the phylogenetic tree. Golovinomyces orontii, an additional powdery mildew species on Chrysanthemum ×morifolium, is reported. This species is rarely found as a spontaneous infection and was obtained from inoculation experiments.