Erysiphe tectonae

Erysiphe tectonae (E.S. Salmon) U. Braun & S. Takam.Schlechtendalia 4: 24, 2000.

Basionym: Uncinula tectonae E.S. Salmon., Ann. Mycol. 5: 479, 1907.

Mycelium epiphyllous, thin, effuse or confluent, forming patches, persistent. Hyphae 3–8μm wide. Hyphal appressoria lobed to multilobed, solitary or in opposite pairs. Conidiophores 60-  90μm long, erect, arising from the upper surface of the mother cells. Foot cells 30–40 × 9.5–12 mm, cylindrical to somewhat curved-sinuous, width somewhat increasing from below to above, followed by 1–2 shorter cells, forming conidia singly. Conidia 30–38 × 15–19μm, ellipsoidovoid to subcylindrical. Conidial appressoria lobate to multilobate (Pseudoidium-type). Sexual morph: Undetermined.

Material examined: On Tectona grandis L. f. (Verbenaceae), THAILAND, Chiang Mai, Suthep, 28 Dec 2013, J. Meeboon, TSU-MUMH1489, GenBank accession number: LC175811; Kanchanaburi Province, Huay Mae Khamin Waterfall, Si Sanat, 22 Feb 2014, J. Meeboon, TSU-MUMH5753.

  Notes: The phylogenetic tree clearly showed that powdery mildew on T. grandis conforms with E. tectonae as it nested with E. tectonae on T. grandis from Indonesia (MUMH3228) with 100% BS support. Braun and Cook (2012) reported E. tectonae on T. grandis from Asia (India and Myanmar). This is the first record of E. tectonae from Thailand.