Dendrostoma castaneae C.M. Tian & N. Jiang

Jiang, Ning, Fan, Xin-Lei, Crous, Pedro W. & Tian, Cheng-Ming, 2019, Species of Dendrostoma (Erythrogloeaceae, Diaporthales) associated with chestnut and oak canker diseases in China, MycoKeys 48, pp. 67-96 : 74

Dendrostoma castaneae C.M. Tian & N. Jiang sp. nov. Figure 4

Diagnosis.

Dendrostoma castaneae is distinguished from the phylogenetically closely related species D. castaneicola by its narrower conidia.

Holotype.

CHINA. Hebei Province: Xinglong County, chestnut plantation, 40°21'44"N, 117°51'29"E, 256 m a.s.l., on branches of Castanea mollissima , 27 Apr. 2018, N. Jiang & C.M. Tian (holotype: BJFC-S1553; ex-type culture: CFCC 52745).

Etymology.

Castaneae, referring to the host genus, Castanea .

Description.

Sexual morph not observed. Asexual morph: Conidiomata pycnidial, pulvinate, occurring separately, bright yellow to orange, immersed in bark, 400-600 μm high, 900-2200 μm diam.; wall of several layers of brown textura angularis; central column beneath the disc irregular, pale yellow. Conidiophores reduced to conidiogenous cells. Conidiogenous cells lining the inner walls of the cavity, hyaline, smooth, subcylindrical to ampulliform, 3-10 × 2-3.5 μm. Conidia hyaline, aseptate, smooth, multiguttulate, thin-walled, ellipsoid, straight to curved, (9.3 –)10.4–12.3(– 13.3) × (2.1 –)2.2–2.7(– 2.9) μm, l/w = (3.4 –)4.2–5.2(– 5.9) (n = 50).

Culture characters.

On PDA, cultures are initially white, exhibiting grey after 2 weeks. Colonies are flat with irregular edge; texture initially uniform, producing concentric circles with faint orange conidiomata distributed outside the rim within 1 month at 25 °C in the dark.

Additional specimens examined.

CHINA. Hebei Province: Chengde City, Xinglong County, chestnut plantation, 40°21'44"N, 117°51'29"E, 256 m a.s.l., on branches of Castanea mollissima , 27 Apr. 2018, N. Jiang & C.M. Tian, living culture CFCC 52748 (BJFC-S1556); Hebei Province: Chengde City, Xinglong County, chestnut plantation, 40°21'44"N, 117°51'29"E, 256 m a.s.l., on branches of Castanea mollissima , 27 Apr. 2018, N. Jiang & C.M. Tian, living culture CFCC 52751 (BJFC-S1557); Hebei Province: Chengde City, Xinglong County, chestnut plantation, 40°21'44"N, 117°51 '29"E, 256 m a.s.l., on branches of Castanea mollissima , 27 Apr. 2018, N. Jiang & C.M. Tian, living culture CFCC 52747 (BJFC-S1559); Hebei Province: Chengde City, chestnut plantation, 40°37'39"N, 118°27'22"E, 256 m a.s.l., on branches of Castanea mollissima , 28 Apr. 2018, N. Jiang & C.M. Tian, living culture CFCC 52750 (BJFC-S1558); Hebei Province: Chengde City, chestnut plantation, 40°37'39"N, 118°27'22"E, 256 m a.s.l., on branches of Castanea mollissima , 28 Apr. 2018, N. Jiang & C.M. Tian, living culture CFCC 52752 (BJFC-S1560); Tianjin City: Jizhou District, chestnut plantation, 40°06'33"N, 117°42'45"E, 185 m a.s.l., on branches of Castanea mollissima , 25 Apr. 2018, N. Jiang & C.M. Tian, living culture CFCC 52749 (BJFC-S1554); Tianjin City: Jizhou District, chestnut plantation, 40°06'33"N, 117°42'45"E, 185 m a.s.l., on branches of Castanea mollissima , 25 Apr. 2018, N. Jiang & C.M. Tian, living culture CFCC 52746 (BJFC-S1555).

Notes.

Dendrostoma castaneae is the most common species in this genus occurring on the host Castanea mollissima in China and is associated with canker symptoms on stems and branches. As shown in Fig. 2, Dendrostoma castaneae is the closest relative of D. castaneicola ; however, they can be distinguished by conidial width (2.2-2.7 μm in D. castaneae vs. 3.2-3.8 μm in D. castaneicola ).