Melanconiella corylina Fan

Fan, Xinlei, Du, Zhuo, Bezerra, Jadson D. P. & Tian, Chengming, 2018, Taxonomic circumscription of melanconis-like fungi causing canker disease in China, MycoKeys 42, pp. 89-124 : 104-105

Melanconiella corylina Fan sp. nov. Fig. 8

Etymology.

corylina (Lat.): referring to the host genus on which it was collected, Corylus .

Diagnosis.

This species is distinguished by acervuli erumpent through circularly cracked host bark and covered by olivaceous buff to honey discharged conidial masses at maturity; conidia unicellular, hyaline, with various shapes and 1-3 guttulate, (7 –)8–13.5(– 14.5) × (2 –)2.5–4(– 5) μm.

Holotype.

CHINA. Shaanxi Province: Baoji County, Taibai Mountain, 34°15'43.32"N, 107°88'42.16"E, 13 July 2017, on twigs and branches of Corylus mandshurica , N. Jiang (BJFC-FB56 holotype; living culture, CFCC 52484).

Descriptions.

Conidiomata acervular, immersed in host bark, erumpent from surface of host branches, scattered or occasionally confluent, 1-1.5 mm, erumpent through circularly cracked host bark and covered by olivaceous buff to honey discharged conidial masses at maturity, usually conspicuous. Ectostromatic disc inconspicuous and cracked circularly at maturity. Central column beneath the disc more or less oblate, iron grey to dark grey. Conidiophores hyaline, smooth, cylindrical, simple, rarely branched at the base. Conidiogenous cells hyaline, phialidic. Conidia unicellular, hyaline, narrowly ellipsoid to fusoid, elongate to slightly allantoid, 1-3 guttulate, (7 –)8–13.5(– 14.5) × (2 –)2.5–4(– 5) μm (av. = 10 × 3.5 µm, n = 50) μm (av. = 13 × 3.5 µm, n = 50). Sexual morph was not observed.

Culture characteristics.

On PDA, cultures are initially white, becoming fuscous black in the centre and edge after 5 d. The colonies are felty with an irregular edge; texture uniform; sterile.

Additional material examined.

CHINA. Shaanxi Province: Baoji County, Taibai Mountain, 34°15'40.05"N, 107°88'43.33"E, 13 July 2017, on twigs and branches of Corylus mandshurica , N. Jiang (CF 20170756 holotype; living culture, CFCC 52485).

Notes.

Melanconiella corylina is associated with canker disease of Corylus mandshurica in China. It can be distinguished from its closest relative, the generic type M. spodiaea growing in Carpinus spp., by its hyaline, discosporina-like conidia, and the smaller size of conidia (8-13.5 × 2.5-4 vs.> 13.3-15.2 × 7.5-8.5 μm) as well as the hosts ( Voglmayr et al. 2012). Melanconiella flavovirens also occurs on Corylus (in Europe and North America), and it can be distinguished from M. corylina based on larger conidia (12-15 × 5.0-5.5 vs.> 8-13.5 ×2.5– 4 μm) ( Voglmayr et al. 2012). The phylogenetic inferences indicated M. corylina as an individual well-supported clade (MP/ML/BI=100/99/1) within Melanconiella and we therefore describe it as new, based on sequence data and morphology.