Colletotrichum doitungense X.Y. Ma, K.D. Hyde & Jayawardena

Ma, Xiaoya, Nontachaiyapoom, Sureeporn, Jayawardena, Ruvishika S., yde, Kevin D., Gentekaki, Eleni, Zhou, Sixuan, Qian, Yixin, Wen, Tingchi & Kang, Jichuan, 2018, Endophytic Colletotrichum species from Dendrobium spp. in China and Northern Thailand, MycoKeys 43, pp. 23-57 : 33

Colletotrichum doitungense X.Y. Ma, K.D. Hyde & Jayawardena sp.nov. Figure 5

Etymology.

In reference to the host sample site Doi tung, Chiang Rai, Thailand.

Holotype.

MFLU 17-1200 (ex-holotype culture: MFLUCC 14-0128).

Description.

Asexual morph on CMA. Vegetative hyphae 1.1-3.5 µm diam, hyaline, smooth-walled, septate, branched. Setae and chlamydospores not observed. Conidiomata and ascomata cluster together. Conidiophores (9.1-) 14.3-26.8 (-29.4) × (3-) 3.1-4.5 (-5) µm, smooth-walled, unbranched, septate, constricted septum, hyaline. Conidiogenous cell (3.1-) 3.2-5.8 (-7.5) × (2.6-) 3-4 (-4.5) µm (N=14), globose to sub-globose, smooth-walled, hyaline. Conidia (6.6-) 8.6-13.8 (-15) × (2.6-) 3.8-8.9 (-13.8) µm (N=22), L/W = 1.75, globose to ellipsoidal, both ends rounded, smooth-walled, hyaline.

Sexual morph on CMA. Ascomata (125.5-) 126.9-133.7 (-135.1) × (101.3-) 101.8-104.3 (-104.8) µm (N=10), sub-globose, closed, pale brown to brown. Peridium 3-11.5 µm thick, Asci (51.1-) 53.7-70.6 (-71.6) × (8.5-) 8.8-10.1 (-10.4) µm (N=8), cylindrical, slight curved, composed of pale to medium brown flattened angular cells, unitunicate, smooth-walled, 8-spored, hyaline. Ascospores (16.1-) 17.5-21.5 (-23.4) × (4.5-) 5.1-7.0 (-7.5) µm (N=20), L/W = 3.2, fusiform, blunt to somewhat acute or acute both ends, single guttule in the middle, septate, bi-seriately, smooth-walled, hyaline.

Cultures on CMA flat with entire margin. Fluffy, white, reverse same. Growth rate: 0.6cm/day, with 20-days for sporulation. Brown ring in the middle. Perithecia gregarious. Acervuli and ascomata in mass light brown to brown.

Material examined.

Thailand, Chiang Rai, Wat Phra That Doi Tung (Temple of Doi Tung Pagodas), the host Dendrobium sp. 2 was collected on 19 December 2013, Collector: Sureeporn Nontachaiyapoom, Natdanai Aewsakul, Xiaoya Ma.

Notes.

Colletotrichum doitungense form an independent lineage from other strains with good support (66ML/1.00BI/73MP) in boninense species complex. The ITS sequence of MFLUCC 14-0128 100% matches with unpublished pathogenic C. cymbidiicola strain OORC18 (GenBank JX902424) isolated from orchid in India and C. karstii strain R001 (GenBank JN715846) isolated from blackberry in Colombia (Unpublished). Blastn researches with sequences of MFLUCC 14-0128 results in 98% identity with GAPDH sequence of endophytic C. boninense strain CGMCC 3.15168 (GenBank KC843491) isolated from Bletilla ochracea in China ( Tao et al. 2013), 99% identity with ACT sequence of C. boninense strain CBS 125502 (GenBank KJ954462) and 99% identity with TUB2 sequence of C. citricola strain SXC 151 (GenBank KC293656) as mentioned above. Its conidiogenus cell is globose to sub-globose, which differ from cylindrical to ellipsoidal conidiogenus cell in C. boninense (Damm et al. 2012). This strain has 2 and 0 in ITS, 6 and 1 in GAPDH, 3 and 2 in ACT, 17 and 16 base pair differences from its sister taxon C. torulosum and MFLUCC 14-0261 respectively. Here we introduce Colletotrichum doitungense isolated from root of Dendrobium sp. 2 as a new species.