Gnomoniopsis chinensis C.M. Tian & N. Jiang sp. nov. Figures 3, 4

Etymology.

Named after the country where it was first collected.

Description.

Pathogenic on stems and branches of Castanea mollissima . Conidiomata pseudostromatic, globose to pulvinate, occurring separately, yellow to orange, semi-immersed in bark, 400-1000 µm high, 500-1500 µm diam, unilocular, single ostiolate, forming long, wide orange tendrils, 1500-2000 µm × 400-500 µm . Conidiophores indistinct, often reduced to conidiogenous cells. Conidiogenous cells oval, hyaline, 1-celled, 6-12 µm . Conidia oval, oblate, fusiform, straight to curved, hyaline, 2-3 guttules, (6.0-)6.5-8.5(-9.0) × (2.2-)2.7-3(-3.5) µm (mean = 7.5 × 2.7 µm).

Culture characters.

Colonies on PDA attaining 90 mm after 20 days at 25 °C, flat, velutinous to shortly woolly, dark brown in center, gradually lightening to pale grey at margin; margin diffuse; reverse of almost same colors as surface.

Specimens examined.

China, Hebei Province, Chengde City, chestnut plantation, 40°24'32.16"N, 117°28'56.24"E, 262 m asl, on stems and branches of Castanea mollissima, Ning Jiang, 11 October 2017 (BJFC-S1380, holotype; ex-type culture, CFCC 52286). Hebei Province, Qinhuangdao City, chestnut plantation, 40°22'52.32"N, 119°11'52.18"E, 246 m asl, on branches and twigs of Castanea mollissima, Ning Jiang, 14 October 2017 (BJFC-S1382, paratype; living culture, CFCC 52288). Hebei Province, Tangshan City, chestnut plantation, 40°12'59.76"N, 117°59'7.24"E, 67 m asl, on stems and branches of Castanea mollissima, Ning Jiang, 18 October 2017 (BJFC-S1383; living culture, CFCC 52289).

Notes.

Three Gnomoniopsis species have been discovered from the host genus Castanea . They share similar conidial dimension (6.0-9.0 × 2.2-3.5 µm in Gnomoniopsis chinensis vs. 5.0-8.0 × 2.0-3.5 µm in G. daii vs. 6.0-9.5 × 2.0-4.0 µm in G. smithogilvyi) (Crous et al. 2012; Jiang and Tian 2019). However, we can distinguish them easily by the phylogram of ITS, tef1 and tub2 (Fig. 2). In addition, Gnomoniopsis chinensis and G. daii inhabit the Chinese chestnut ( Castanea mollissima), but G. smithogilvyi on the European chestnut ( C. sativa) and C. crenata × C. sativa hybrids.