Graphilbum anningense H. Wang, Q. Lu & Z. Zhang

Min Wang, Hui, Wang, Zheng, Liu, Fu, Xu Wu, Cheng, Fang Zhang, Su, Kong, Xiang Bo, Decock, Cony, Lu, Quan & Zhang, Zhen, 2019, Differential patterns of ophiostomatoid fungal communities associated with three sympatric Tomicus species infesting pines in south-western China, with a description of four new species, MycoKeys 50, pp. 93-133 : 104-107

Graphilbum anningense H. Wang, Q. Lu & Z. Zhang sp. n. Fig. 11

Etymology.

‘anningense’ (Latin), referring to the type locality.

Type.

CHINA, Yunnan, Tomicus yunnanensis galleries in Pinus yunnanensis , Apr. 2017, HM Wang, holotype CXY 1939, culture ex-holotype CFCC 52631 = CXY 1939.

Description.

Sexual form: unknown.

Asexual forms: Pesotum -like and Hyalorhinocladiella -like. Pesotum -like conidiophores abundant on 2% MEA, macronematous, synnematous, (150-) 210-293 (-336) μm long including conidiogenous apparatus, the base dark brown, slightly widened, (6.7-) 7.9 -18.8 (-29.0) μm wide anchored in the media by brown rhizoid-like hyphae, the apex slightly enlarging, fan-shaped; conidiogenous cells hyaline, thin-walled, aseptate, (15.3-) 21.0-35.5 (-42) × (0.7-) 1.1-1.9 (-2.3) μm; conidia 1-celled, clavate, ellipsoid to ovoid with truncate base and rounded apex, hyaline, smooth, (3.1-) 3.6-6.3 (-9.7) × (1.4-) 1.6-2.2 (-2.5) μm.

Hyalorhinocladiella -like: conidiogenous cells macronematous or semi-macronematous, mononematous, hyaline, simple or loosely branched, thin-walled, aseptate, (4.5-) 10.8-29.0 (-47) × (1.5-) 1.7-2.3 (-2.6) μm; conidia hyaline, clavate to ellipsoid, with obtuse ends, 1-celled, aseptate, smooth, (3.7-) 4.5-6.4 (-9.0) × (1.4-) 1.7-2.3 (-2.9) μm.

Culture characteristics.

Colonies on 2% MEA in the dark reaching 90 mm in diam. in 6 days at 25 °C, growth rate up to 19.5 mm/day at the fastest; colony margin smooth. Mycelium superficial to flocculose or floccose, hyaline; reverse hyaline to pale yellowish. Optimal growth temperature 30 °C, slow growth at 40 °C, no growth at 5 °C.

Known substrate and hosts.

Galleries of Tomicus yunnanensis and T. minor in Pinus yunnanensis .

Known insect vectors.

Tomicus yunnanensis , T. minor .

Known distribution.

Yunnan Province, China.

Additional specimens examined.

CHINA, Yunnan, Tomicus yunnanensis , T. minor galleries in Pinus yunnanensis , Apr. 2017, HM Wang, CFCC 52632 = CXY 1940, CFCC 52633 = CXY 1944.

Note.

Graphilbum anningense is characterised by a Pesotum -like and a Hyalorhinocladiella -like asexual state. It is phylogenetically closely related to Gra. rectangulosporium . However, Gra. rectangulosporium produced a sexual state in vitro ( Ohtaka et al. 2006) which has not been observed in Gra. anningense . Other morphologically similar species include Gra. fragrans , Gra. crescericum , Gra. kesiyae and Gra. puerense . Graphilbum kesiyae and Gra. puerense also produce a Pesotum -like and a Hyalorhinocladiella -like asexual state. Graphilbum anningense and Gra. kesiyae differ by the size of their synnemata, whose length ranges do not overlap, viz. 210-293 μm and 112.5-173 μm long ( Harrington et al. 2001), respectively. They also differ by their optimal growth temperature, respectively 30°C and 25°C. The synnemata of Gra. puerense , 206-357 μm long ( Chang et al. 2017), are marginally longer than those of Gra. anningense . Graphilbum fragrans and Gra. crescericum produce only a Leptographium -like and/or a Hyalorhinocladiella -like asexual state in vitro ( Harrington et al. 2001, Chang et al. 2017).

Graphilbum anningense was isolated from galleries of T. yunnanensis and T. minor infesting P. yunnanensis . Previously, Gra. fragrans had been reported from T. yunnanensis infesting P. yunnanensis and from Pissodes spp. infesting Tsuga dumosa and P. armandii in China ( Paciura et al. 2010, Zhou et al. 2013). Graphilbum kesiyae and Gra. puerense were isolated from galleries of Polygraphus aterrimus , Po. szemaoensis and Ips acuminatus infesting P. kesiya ( Chang et al. 2017). Although the geographic distribution of these four Graphilbum species overlaps, their hosts and vectors are nevertheless, as far as it is known, different ( Chang et al. 2017).