| Strain | 12031 |
|---|---|
| Classification | Xylariales, Microdochiaceae, Microdochium |
| Culture collection | BCRC FU31185 |
| Detection frequency | Medium |
| Figure |  Fig. 1 5-day-old colony on PDA  Fig. 2 Microdochium pinatubo. Ex-type strain CBS 158.94. a–d. Colonies at 25 °C after 5 d. a–b. PDA. c–d. OA. e–f, i–j. Aerial conidiophores and conidia. g–h. Aerial conidiophores and sporodochia on OA media. k–l. Sporodochia. m. Conidia produced by sporodochia. n. Conidia produced by aerial conidiophores. o. Prolonged, septated conidia produced by aerial conidiophores in aged culture (Bars= 5 μm, unless otherwise specified) |
| Colonies | Colonies on PDA attaining 27-, 39-, 47-, 49-, 42-mm under 16 °C, 20 °C, 24 °C, 28 °C, 32 °C after 5 days, respectively, floccose with abundant white aerial mycelium, pale orange near the center. Reverse pale orange, slightly zonate. Sporulation abundant with submerged sporulation, concentric rings of sporulation occasionally present. White, globose mycelial tufts up to 15 mm in diameter occasionally observed in old culture (> 2 wk). Colonies on OA powdery, white to pale orange, slighty zonate. Sporulation abundant with submerged sporulation, concentric rings of sporulation often present. |
| Sporodochia | Sporodochia present, superficial or submerged in the agar, slimy, salmon. Sporodochial conidiophores macronematous or micronematous, hyaline, short, simple or branched. Sporodochial conidiogenous cells discrete, hyaline, flask-shape, laterally or terminally, sympodial, often in whorls, 6.5–11.0 × 2.0–3.0 μm, necks often elongated, slightly denticulate and geniculate when aged. Sporodochia conidia slimy, hyaline, fusiform with both ends pointed, aseptate, 5.0–6.5 × 2.0–2.5(–3.0) μm. |
| Conidiophores | Aerial conidiophores hyaline, erect, smooth, 1.5–2.5 μm wide near the basal septa, tapering towards the apex, mostly simple in young culture (< 1 wk). Branched conidiophores arised in old culture (> 2 wk), often branched at right angle, especially for the branches at the upper parts of conidiophores. |
| Conidiogenous cells | Aerial conidiogenous cells integrated, hyaline, terminal or intercalary, sympodial, often swollen and denticulate, bearing up to 8 conidia. |
| Conidia | Aerial conidia dry, hyaline, obovoid, base tapered and acute, apex rounded, aseptate, 5.5–8.5 × 2.0–3.5 μm. Elongated, septate conidia can be found in old culture (> 2 wk), 1-septate, often guttulated, 7.0–11.5 × 2.5–3.5 μm. |
| Chlamydospores | Chlamydospores not observed. |
| Note | Manandhar and Mew (1996) reported a new genus with single species, Pinatubo oryzae, which was frequently isolated from rice grains. Based on the morphological and molecular analyses., this species should be transferred to Microdochium. As the name “Microdochium oryzae” has been used previously, a new name, Microdochium pinatubo, for this species is indispensable. In the original description of Pinatubo oryzae (Manandhar and Mew, 1996), the conidia produced on solitary aerial conidiophores were 1-septate, 6.7–10.2 × 2.2–3.3 μm (on rice grains), 6.9–11.3 × 2.4–3.5 μm (on WA). In this study, it was found that conidia from aerial conidiophores were aseptate and shorter in length in young culture (< 1 wk). Elongated, 1-septate conidia conforming the original description could only be observed from old culture (> 2 wk). Certainly the effect of culture age on conidial morphology was overlooked by the original description (Manandhar and Mew, 1996). This character has be confirmed in this study after examining the type material from CBS 158.94. Yellowish, intercalary chlamydospores were observed by Manandhar and Mew (1996) on the surface of PDA from CBS 158.94. However, such chlamydospores were not observed after examining the type material. Hernández-Restrepo et al. (2016) proposed a new species, Microdochium fisheri, typified by CBS 242.91 (from rice stem, misspelled as CBS 242.90 on the website of CBS). In this study, it was found that Microdochium fisheri morphologically resembled Microdochium pinatubo (Pinatubo oryzae) and CBS 242.91 were identical to CBS 158.94 in the ITS, LSU, TUB and RPB2 regions This species should be a synonym of Microdochium pinatubo.
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| Pathogenicity | Unknown |
| Specimens examined | Taiwan, Tainan City, rice grains, Jan 2011, Jie-Hao Ou, 12025 Taiwan, Yunlin County, rice grains, Jan 2011, Jie-Hao Ou, 12027 Taiwan, Yunlin County, rice grains, Jan 2011, Jie-Hao Ou, 12029 Taiwan, Yunlin County, rice grains, Mar 2012, Jie-Hao Ou, 12031 Taiwan, Chiayi County, rice grains, Apr 2012, Jie-Hao Ou, 12033 |
| ITS | GGTGAACCTGCGGAGGGATCATTACAGAGTTATCTAACTCCCAAAACCATGTGAACTTACCACTGTTGCCTCGGTGGAAGGCGCTGGAAACAGCGCTGGAAGCCGGTGGACATCTAAACTCTTGTTAATTTTTGGCATTCTGAATCATAACTAAGAAATAAGTTAAAACTTTCAACAACGGATCTCTTGGTTCTGGCATCGATGAAGAACGCAGCGAAATGCGATAAGTAATGTGAATTGCAGAATTCAGTGAATCATCGAATCTTTGAACGCACATTGCGCCCATTAGTATTCTAGTGGGCATGCCTGTTCGAGCGTCATTTCAACCCTTAAGCCTAGCTTAGTGTTGGGAGACTGCCTAATACGCAGCTCCTCAAAACCAGTGGCAGAGTTTTTACGTACTCTGAGCGCAGTAATTCTATTCTCGCTTCTGAAAACGTCTAGACGATAGCCAGAAACCGCATGCTTCGGCAGCACTTTTTAATGGTTGACCTCGGATCAGGTAGG |