Eight of 14 phylogenetic species identified in this study were shown to represent distinct terminal clades, and are interpreted as new species of Ophiostoma.
Ophiostoma genhense Z. Wang & Q. Lu, sp. nov.
MycoBank MB 830610.
(Fig. 12)
Etymology: The epithet genhense (Latin) refers to the city of Genhe, from which this fungus was collected.
Diagnosis: The species is characterized by perithecia and synnematous conidiophores. It can be differentiated from the closely related species O. multisynnematum by the presence of perithecia, absent in latter, and smaller synnemata. Over time, the O. genhense colonies gradually turned brown from the centre, whereas the colonies of O. multisynnematum turned dark olivaceous.
Type: China, Inner Mongolia Autonomous Region: Genhe, from Ips subelongatus infesting Larix gmelinii, Sept. 2017, Q. Lu (CXY 2001 – holotype; CFCC 52675 – ex-type culture).
Description: Sexual morph perithecial. Perithecia few on 2% MEA after 20 d, developing on a superficial mycelium or partly embedded in the agar, bases black, (103–) 114–156 (− 164) μm diam., with some basal hyphal ornamentation, dark brown to black; necks black, cylindrical, straight or slightly curved, (135–) 210–347 (− 400) μm long, (17–) 21.5–32.5 (− 38) μm wide at the base down to (8.5–) 12.5–17 (− 18.5) μm wide at the apex, composed of parallel, septate, laterally fused hyphae, ending in a crown of hyaline. Ostiolar hyphae occasionally present, 6.5–13 (− 18) μm long. Ascospores hyaline, allantoid or crescent in side view, without sheath, aseptate, (3.5–) 4–5 (− 6) × (1.5–) 2 (− 2.5) μm.
Asexual morphs: pesotum-like and hyalorhinocladiella-like.
Pesotum-like morph: synnemata solitary or in groups, the base black, (22.5–) 24.5–45.5 (− 48.5) μm wide, (170–) 184–257 (− 271) μm tall, including the conidiogenous apparatus. Conidiogenous cells (12–) 15–23 (− 26.5) × 1.5–2 μm. Conidia hyaline, smooth, cylindrical, aseptate, (3–) 3.5–4 (− 4.5) × 2–2.5 μm. Hyalorhinocladiella-like morph: conidiogenous cells arising directly from the hyphae, (25–) 30.5–43 (− 44) × 1.5–2 μm. Conidia hyaline, smooth, ovate to cylindrical, aseptate, (3.5–) 4–5.5 (− 7) × (2.5–) 3–3.5 (− 4) μm.
Cultures: Colonies on 2% MEA at 25 °C reaching 80 mm diam. in 10 d, initially hyaline, later becoming brown, mycelium superficial or sparsely aerial, the colonies edge thinning radially, synnemata and perithecia scattered in the centre. Optimal temperature for growth at 25 °C, no growth observed at 5 °C and 35 °C.
Ecology: Isolated from Ips subelongatus infesting dying Larix gmelinii and stock log.
Habitat: L. gmelinii pure plantation.
Distribution: Currently only known from the Inner Mongolia Autonomous Region, China.
Notes: Ophiostoma genhense and O. multisynnematum formed two distinct, well-supported clades within the O. piceae complex (Fig. 3), in which they were closely related to O. breviusculum (Chung et al. 2006). They can be both differentiated from O. breviusculum by the presence of a hyalorhinocladiella-like asexual state, which is absent in the latter.
Additional specimens examined: China: Inner Mongolia Autonomous Region: Genhe, from Ips subelongatus infesting Larix gmelinii, Sept. 2017, Q. Lu (cultures CXY 2002, CFCC 52676).
Ophiostoma hongxingense Z. Wang & Q. Lu, sp. nov.
MycoBank MB 830611.
(Fig. 13)
Etymology: The epithet hongxingense (Latin) refers to the city of Hongxing, from which this fungus was collected.
Diagnosis: See comparisons between Ophiostoma hongxingense and O. subelongati under O. subelongati.
Type: China: Heilongjiang province: Hongxing, from Ips subelongatus on Larix gmelinii, July 2017, Q. Lu (CXY 2021 – holotype; CFCC 52695 – ex-type culture).
Description: Sexual morph not observed.
Asexual morph: hyalorhinocladiella-like.
Hyalorhinocladiella-like morph: conidiogenous cells arising directly from superficial hyphae, (10.5–) 14–22.5 (− 28.5) × (1.5–) 2–2.5 (− 3) μm. Conidia hyaline, smooth, ovate to elliptical, aseptate, (5–) 5.5–6.5 (− 8) × (2–) 2.5–3.5 (− 4) μm.
Cultures: Colonies on 2% MEA at 25 °C reaching 58 mm diam. in 5 d, initially hyaline, discoloring progressively to dark olivaceous from the centre of the colonies to the margin, the colonies edge thinning radially; mycelium superficial on the agar. Optimal temperature for growth at 30 °C, no growth observed at 5 °C and 40 °C.
Ecology: Isolated from Ips subelongatus infesting dying Larix gmelinii and L. olgensis.
Habitat: L. gmelinii or L. olgensis pure plantation.
Distribution: Currently known from the Inner Mongolia Autonomous Region and Heilongjiang province, China.
Notes: See comparisons between Ophiostoma hongxingense and O. subelongati under O. subelongati.
Additional specimens examined: China: Heilongjiang province, Zhanhe, from Ips subelongatus infesting Larix gmelinii, July 2017, Q. Lu (cultures CXY 2022 = CFCC 52696; CXY 1905; CXY 1906; CXY 1907); Jiamusi, from Ips subelongatus infesting Larix olgensis. Aug. 2011, Q. Lu (culture CXY 1924).
Ophiostoma lotiforme Z. Wang & Q. Lu, sp. nov.
MycoBank MB 830612.
(Fig. 14)
Etymology: The epithet lotiforme (Latin) refers to lotus-shaped conidiomata composed of clustered synnemata.
Diagnosis: The compound, lotus-shaped conidiomata are unique, and its synnemata are distinctly taller than those of the related species O. saponiodorum, respectively (876–) 945–1224 (− 1290) μm vs. (118–) 188–297 (− 370) μm. Synnemata are absent in O. pallidulum (Linnakoski et al. 2010). Ophiostoma lotiforme also grows slower than O. saponiodorum on 2% MEA. In addition, no growth of O. saponiodorum is observed at 35 °C, but O. lotiforme grows at 35 °C; no growth of O. lotiforme is observed at 40 °C, but O. pallidulum grows at 40 °C.
Type: China: Inner Mongolia Autonomous Region, Hailar, from Ips subelongatus on Pinus sylvestris var. mongolica, Aug. 2010, X. Meng (CXY 2017 – holotype, CFCC 52691 = MUCL 55165 – ex-type culture).
Description: Sexual morph not observed.
Asexual morphs: pesotum-like and hyalorhinocladiella-like.
Pesotum-like morph: synnemata occurring in groups, the base hyaline, (78.5–) 81.5–91.5 (− 94) μm wide, (876–) 945–1224 (− 1290) μm tall including the conidiogenous apparatus. Conidiogenous cells (12–) 15–23 (− 28.5) × (1.5–) 2–2.5 μm. Conidia hyaline, smooth, clavate to ovate, aseptate, 4–5.5 (− 6) × 2–2.5 μm; compound, lotus–shaped, pesotum-like conidiomata, pure white, (898–) 971–1296 (− 1450) μm wide at base, (964–) 1019–1427 (− 1655) μm tall. Hyalorhinocladiella-like morph: conidiogenous cells arising from superficial hyphae, (6–) 11–22 (− 28.5) × 1.5–2.5 (− 3) μm. Conidia hyaline, aseptate, smooth, clavate to ovate, (3.5–) 4–5.5 (− 6.5) × (2–) 2.5–3.5 (− 4) μm.
Cultures: Colonies on 2% MEA at 25 °C reaching 65 mm diam. in 15 d, pure white, the colonies margin smooth; mycelium superficial on the agar. Optimal temperature for growth at 30 °C, no growth observed at 5 °C and 40 °C.
Ecology: Isolated from Ips subelongatus infesting dying Pinus sylvestris var. mongolica.
Habitat: Mixed forest of P. sylvestris var. mongolica and L. gmelinii.
Distribution: Currently only known from the Inner Mongolia Autonomous Region, China.
Notes: Ophiostoma lotiforme pertains to the O. saponiodorum lineage, in which it is closely related to O. saponiodorum and O. pallidulum (Figs. 2, 9, and 10). These species share a hyalorhinocladiella-like asexual state (Linnakoski et al. 2010).
Additional specimens examined: China: Inner Mongolia Autonomous Region, Hailar, from Ips subelongatus infesting Pinus sylvestris var. mongolica, Aug. 2010, X. Meng (cultures CXY 2018 = CFCC 52692).
Ophiostoma multisynnematum Z. Wang & Q. Lu, sp. nov.
MycoBank MB 830614.
(Fig. 15)
Etymology: The epithet multisynnematum (Latin) referring to the numerous synnemata.
Diagnosis: See comparisons among Ophiostoma multisynnematum, O. genhense, and O. breviusculum below the description of O. genhense.
Type: China: Inner Mongolia Autonomous Region, Genhe, from Ips subelongatus infesting Larix gmelinii, Sept. 2017, Q. Lu (CXY 2003 – holotype; CFCC 52677 – ex-type culture).
Description: Sexual morph not observed.
Asexual morphs: pesotum-like and hyalorhinocladiella-like.
Pesotum-like morph: synnemata occurring singly or in groups, the base black, (11–) 12.5–43.5 (− 73) μm wide, (256–) 307–433 (− 544) μm tall including conidiogenous apparatus. Conidiogenous cells (12–) 17.5–31.5 (− 45) × 1.5–2 (− 2.5) μm. Conidia hyaline, smooth, cylindrical, aseptate, 5.5–7 (− 8.5) × (2–) 2.5–3 (− 3.5) μm. Hyalorhinocladiella-like morph: conidiogenous cells arising from superficial hyphae, (9–) 13–33.5 (− 50.5) × (1.5–) 2–2.5 (− 3) μm. Conidia hyaline, smooth, ovate to cylindrical, aseptate, (4–) 4.5–5.5 (− 6.5) × 2.5–3.5 (− 4.5) μm.
Cultures: Colonies on 2% MEA at 25 °C reaching 78 mm in diameter in 10 d, initially hyaline, thinning radially toward the margin, later becoming dark olivaceous and massive synnemata arising in the centre; hyphae superficial, aerial mycelium sparse. Optimal temperature for growth at 25 °C, no growth observed at 5 °C and 35 °C.
Ecology: Isolated from Ips subelongatus infesting dying Larix gmelinii and stock log.
Habitat: L. gmelinii pure plantation.
Distribution: Currently only known from the Inner Mongolia Autonomous Region, China.
Notes: See comparisons among Ophiostoma multisynnematum, O. genhense, and O. breviusculum below the description of O. genhense.
Additional specimens examined: China: Inner Mongolia Autonomous Region, Genhe, from Ips subelongatus infesting Larix gmelinii, Sept. 2017, Q. Lu (cultures CXY 2004 = CFCC 52678; CXY 1917; CXY 1918; CXY 1919).
Ophiostoma peniculi Z. Wang & Q. Lu, sp. nov.
MycoBank MB 830609.
(Fig. 16)
Etymology: The epithet peniculi (Latin) refers to the brush-like conidiomata.
Diagnosis: Ophiostoma peniculi, O. macroclavatum, and O. pseudocatenulatum can be distinguished from each other by the sizes of their synnemata and conidia. In decreasing order, the size ranges of their synnemata are (2184–) 3117–5172 (− 6330) μm in O. macroclavatum, (1366–) 1931–3696 (− 4534) μm in O. pseudocatenulatum and (875) 945–1224 (− 1290) μm in O. peniculi. The width ranges of their conidia are, in decreasing order, 2–2.5 μm in O. peniculi, 1.5–2 (− 3) μm in O. macroclavatum, and (0.5–) 1–1.5 (− 2) μm in O. pseudocatenulatum. Ophiostoma peniculi colonies also grow faster than the above two species on 2% MEA at 25 °C. The optimal growth temperature is also different for O. peniculi (30 °C) and O. macroclavatum (25 °C). As for O. peniculi, no growth was observed at 5 °C and 40 °C, but O. pseudocatenulatum can still grow at 5 °C (Linnakoski et al. 2016).
Type: China: Heilongjiang province, Hongxing, from Ips subelongatus infesting Larix gmelinii, Sept. 2017, Q. Lu (CXY 2013 – holotype, CFCC 52687 – ex-type culture).
Description: Sexual morph not observed.
Asexual morphs: pesotum-like and hyalorhinocladiella-like.
Pesotum-like morph: synnemata brush-like, occurring in groups, milky white, (875–) 945–1225 (− 1290) μm long including conidiogenous apparatus, (78.5–) 81.5–91.5 (− 94) μm wide at base. Conidiogenous cells (13.5–) 17.5–26.5 (− 32) × (1.5–) 2–2.5 μm. Conidia hyaline, smooth, cylindrical, aseptate, (4–) 5–6 (− 6.5) × 2–2.5 μm. Hyalorhinocladiella-like morph: conidiogenous cells arising directly from aerial hyphae, (7.5–) 10.5–21 (− 33.5) × (1.5–) 2–2.5 (− 3) μm. Conidia hyaline, aseptate, smooth, cylindrical, (5–) 5.5–6.5 (− 8) × (28–) 2.5–3.5 (− 4) μm.
Cultures: Colonies on 2% MEA at 25 °C reaching 75 mm diam. in 5 d, initially hyaline, the colonies edge thinning radially, becoming dark olivaceous in the centre; mycelium mostly superficial, sparsely aerial. Optimal temperature for growth at 30 °C, no growth observed at 5 °C and 40 °C.
Ecology: Isolated from Ips subelongatus infesting dying Larix gmelinii and L. olgensis.
Habitat: L. gmelinii or L. olgensis pure plantation.
Distribution: Currently known from the Inner Mongolia Autonomous Region and Heilongjiang province, China.
Notes: In a phylogenetic perspective, O. peniculi is closely related to O. hongxingense, O. subelongati, O. macroclavatum, O. pseudocatenulatum, and O. brunneolum (Fig. 6). Ophiostoma peniculi is characterized by brush-like synnemata, which are absent in O. hongxingense, O. subelongati (see below), and O. brunneolum (Linnakoski et al. 2016).
Additional specimens examined: China: Heilongjiang province, Zhanhe, from Ips subelongatus infesting Larix gmelinii, Sept. 2017, Q. Lu (cultures CXY 2014 = CFCC 52688; CXY 1904); Jiamusi, from Ips subelongatus infesting Larix olgensis, Aug. 2011, Q. Lu (culture CXY 1920).
Ophiostoma pseudobicolor Z. Wang & Q. Lu, sp. nov.
MycoBank MB 830615.
(Fig. 17)
Etymology: The epithet pseudobicolor (Latin) refers to the morphological resemblance and phylogenetic affinities with O. bicolor.
Diagnosis: Ophiostoma pseudobicolor is the closest phylogenetic relative to O. bicolor. Morphologically, these two species differ by the size of their perithecia, with globose bases ranging from (308–) 350–480 (− 536) μm in O. pseudobicolor vs. 175–350 (− 365) μm in O. bicolor (Upadhyay 1981). The necks of O. pseudobicolor are more robust than those of O. bicolor, especially at the apex [viz. (43–) 49–68 (− 77) μm vs. 15–42 (− 50) μm].
Type: China: Inner Mongolia Autonomous Region, Genhe, from Ips subelongatus infesting Larix gmelinii, Sept. 2017, Q. Lu (CXY 2009 – holotype, CFCC 52683 – ex-type culture).
Description: Sexual morph perithecial. Perithecia developing on 2% MEA at 25 °C after 15 d from superficial or embedded mycelium, superficial or partly embedded in the agar medium, with the base globose, subhyaline to yellow orange, (309–) 350–480 (− 536) μm diam., extending into a filiform neck; bases globose, prolonged by a cylindrical, straight or slightly curved, occasionally twinning neck, black (663–) 754–1100 (1358) μm long, (33–) 55–77 (− 79) μm wide at the base down to (43–) 49–68 (− 77) μm wide at the apex, composed of densely packed septate hyphae with a parallel orientation. Ostiolar hyphae absent. Ascospores hyaline, elliptical to oblong with obtuse ends in side and face view, circular in pole view, surrounded by a thick, hyaline gelatinous sheath appearing ossiform in side and face views, quadrangular with flanged corners in the end view, aseptate, (5.5–) 6–6.5 (− 7) × (3–) 3.5–4 (− 4.5) μm, included sheath.
Asexual morph: hyalorhinocladiella-like.
Hyalorhinocladiella-like morph: conidiogenous cells arising directly from the hyphae, (14–) 21.5–43.5 (− 60.5) × (2–) 2.5–4 (− 4.5) μm. Conidia hyaline, smooth, cylindrical, aseptate, (8.5–) 10–12 (− 13) × (4–) 4.5–5.5 (− 6) μm.
Cultures: Colonies on 2% MEA at 25 °C, fast growing, reaching 80 mm diam. in 5 d, effuse, cottony, hyaline to white at first, becoming white gray or gray brown; hyphae submerged in agar with many aerial mycelium. Optimal temperature for growth at 30 °C, no growth observed at 5 °C or 40 °C.
Ecology: Isolated from Ips subelongatus infesting dying Larix gmelinii, L. olgensis and L. principis-rupprechtii.
Habitat: L. gmelinii, L. olgensis or L. principis-rupprechtii pure plantation.
Distribution: Currently known from the Inner Mongolia Autonomous Region and Heilongjiang province, China.
Notes: Ophiostoma pseudobicolor is characterized by perithecium with a light-colored base extending into a dark neck. Similarly colored perithecia have been identified in O. bicolor (Upadhyay 1981), which also is the closest phylogenetic relative to O. pseudobicolor (Figs. 7, 8). However, DNA sequences of ITS and βT (Figs. 7, 8) clearly showed that both species represent two distinct clades.
Additional specimens examined: China: Inner Mongolia Autonomous Region, Genhe, from Ips subelongatus infesting Larix gmelinii, Sept. 2017, Q. Lu (cultures CXY 2010; CFCC 52684); Chifeng, from Ips subelongatus infesting Larix principis-rupprechtii, Aug. 2011, Q. Lu (cultures CFCC 52685; CXY 2011 = MUCL 55168; 1910); Heilongjiang, Mohe, from Ips subelongatus infesting Larix principis-rupprechtii, May 2012, Q. Lu (cultures CFCC 52686; CXY 2012 = MUCL 55174); Tahe, from Ips subelongatus infesting Larix gmelinii, May 2012, Q. Lu (culture CXY 1911 = MUCL 55170); Jiamusi, from Ips subelongatus infesting Larix olgensis, Aug. 2011, Q. Lu (culture CXY 1925; CXY1926).
Ophiostoma subelongati Z. Wang & Q. Lu, sp. nov.
MycoBank MB 830616.
(Fig. 18)
Etymology: The epithet subelongati (Latin) refers to the vector (Ips subelongatus) from which this fungus was isolated.
Diagnosis: Ophiostoma subelongati colonies gradually turned brownish grey from the centre, but the O. hongxingense colonies centre turned dark olivaceous.
Type: China: Heilongjiang province, Hongxing, from Ips subelongatus infesting Larix gmelinii. July 2017, Q. Lu (CXY 2019 – holotype, CFCC 52693 – ex-type culture).
Description: Sexual morph not observed.
Asexual morph: hyalorhinocladiella-like.
Hyalorhinocladiella-like morph: conidiogenous cells arising directly from superficial hyphae, (11.5–) 12.5–27 (− 28) × 2–3 μm. Conidia hyaline, smooth, elliptical, aseptate, (4.5–) 5.5–7 (− 8.5) × 2.5–3.5 (− 4) μm.
Cultures: Colonies on 2% MEA at 25 °C reaching 61 mm diam. in 5 d, initially hyaline, the colonies edge thins radially, then from the centre of the colonies to the periphery it becomes brownish grey and develops superficial mycelium on the agar. Optimal temperature for growth is 30 °C; no growth observed at 5 °C or 40 °C.
Ecology: Isolated from Ips subelongatus infesting dying Larix gmelinii and L. olgensis.
Habitat: L. gmelinii or L. olgensis pure plantation.
Distribution: Currently known from the Inner Mongolia Autonomous Region and Heilongjiang province, China.
Notes: Ophiostoma subelongati forms a distinct clade within the O. clavatum complex (Linnakoski et al. 2016), in which it is closely related to O. hongxingense, O. peniculi, O. macroclavatum, O. pseudocatenulatum, and O. brunneolum (Fig. 6). These species share a similar hyalorhinocladiella-like state. Ophiostoma peniculi, O. macroclavatum, and O. pseudocatenulatum can be distinguished from O. subelongati and O. hongxingense by the presence of synnemata, which is absent from the latter two. The optimal growth temperature of O. peniculi, O. subelongati, and O. hongxingense is 30 °C, while that of O. macroclavatum and O. brunneolum is 25 °C. For O. subelongati and O. hongxingense, no growth observed at 5 °C and 40 °C, but O. pseudocatenulatum can still grow at 5 °C. In terms of colonies characteristics, O. peniculi, O. subelongati, and O. hongxingense grow faster than the above three species on 2% MEA at 25 °C.
Additional specimens examined: China: Heilongjiang province, Hongxing, from Ips subelongatus infesting Larix gmelinii, July 2017, Q. Lu (culture CXY 2020 = CFCC 52694; CXY 1921; CXY 1922); Jiamusi, from Ips subelongatus infesting Larix olgensis, Aug. 2011, Q. Lu (culture CXY 1923).
Ophiostoma xinganense Z. Wang & Q. Lu, sp. nov.
MycoBank MB 830617.
(Fig. 19)
Etymology: The epithet xinganense (Latin) refers to the Xing’an mountains from where this taxon was first isolated.
Diagnosis: Ophiostoma xinganense is closely related to O. rufum. Ophiostoma xinganense develops three synanamorphs, pesotum-like, sporothrix-like and hyalorhinocladiella-like asexual states, but O. rufum has pesotum-like and sporothrix-like states and lacks hyalorhinocladiella-like state (Jankowiak et al. 2019). Both sporothrix-like and pesotum-like asexual states have been observed in both species, but their conidia are different in shape and size. Conidia of sporothrix-like asexual state is ovate to oblong shape with 4–5.5 (− 7) × (2–) 2.5–4 (− 4.5) μm in O. xinganense vs. clavate or fusiform (primary conidia) with (7.2–) 8.9–12.4 (− 15.2) × (2–) 2.5–3.1 (− 3.4) μm in O. rufum, showing the former much smaller and rounder compared to the latter. Conidia of pesotum-like asexual state is ovate to oblong shape with 3.5–4.5 (− 5) × 2–2.5 μm in O. xinganense vs. oblong to curved shape with (2.5–) 3.3–4.5 (− 6.2) × (1.2–) 1.4–1.7 (− 2.2) μm in O. rufum, showing the former wider and rounder than the latter.
Type: China: Inner Mongolia Autonomous Region, Genhe, from Ips subelongatus infesting Larix gmelinii, Sept. 2017, Q. Lu (CXY 2005 – holotype, CFCC 52679 – ex-type culture).
Description: Sexual morph not observed.
Asexual morphs: pesotum-like, sporothrix-like and hyalorhinocladiella-like.
Pesotum-like morph: synnemata solitary or in groups, base black, (16.5–) 29.5–80 (− 114.5) μm wide, (446–) 483–768 (− 953) μm tall including the conidiogenous apparatus. Conidiogenous cells (11–) 13–23.5 (− 29.5) × (1–) 1.5–2 μm. Conidia hyaline, smooth, ovate to oblong, aseptate, 3.5–4.5 (− 5) × 2–2.5 μm. Sporothrix-like morph: conidiogenous cells arising directly from hyphae, (15.5–) 21.5–49.5 (− 79) × 1.5–2 (− 2.5) μm. Conidia hyaline, smooth, ovate to oblong, aseptate, 4–5.5 (− 7) × (2–) 2.5–4 (− 4.5) μm. Hyalorhinocladiella-like morph: conidiogenous cells arising directly from hyphae, (9.5–) 11–18.5 (− 23) × 1.5–2 (− 2.5) μm. Conidia hyaline, smooth, ovate to oblong, aseptate, (4–) 4.5–5 (− 5.5) × 3–4 μm.
Cultures: Colonies on 2% MEA at 25 °C reaching 75 mm diam. in 10 d, initially whitish gray, the colonies edge thinning radially; hyphae mostly superficial, sparsely aerial, synnemata developing abundantly in the colonies centre. Optimal temperature for growth at 25 °C, no growth observed at 5 °C and 40 °C.
Ecology: Isolated from Ips subelongatus infesting dying Larix gmelinii and stock log.
Habitat: L. gmelinii pure plantation.
Distribution: Currently only known from the Inner Mongolia Autonomous Region, China.
Notes: Ophiostoma xinganense is closely related to O. rufum and O. brunneum (Hausner et al. 2003, Jankowiak et al. 2019) (Fig. 3). Ophiostoma xinganense and O. rufum can be distinguished from O. brunneum by the presence of a pesotum-like asexual state, which is absent in the latter. In terms of colony characteristics, O. xinganense colonies are whitish gray with edge thinning radially and exhibits a clear concentric pattern of cream-colored rings, but O. rufum colonies were brownish orange to a rust brown with margin smooth and without concentric rings. Furthermore, at their optimal growth temperature (25 °C), physiologically O. xinganense shows a radial growth over three times faster than that reported in O. rufum under the same conditions on 2% MEA (7.5 mm/d vs. 2.2 mm/d, Jankowiak et al. 2019). In addition, O. xinganense can grow at 30 and 35 °C, but O. rufum can not at both temperatures.
Additional specimens examined: China: Inner Mongolia Autonomous Region, Genhe, from Ips subelongatus infesting Larix gmelinii, Sept. 2017, Q. Lu (cultures CXY 2006 = CFCC 52680; CXY 1901; CXY 1902; CXY 1903).