Sheathospora 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 : 106-107

Sheathospora Fan gen. nov.

Etymology.

Sheathospora (Lat.): referring to the conidia with distinct hyaline sheath.

Diagnosis.

This genus differs from other genera in Melanconiellaceae by conical and discrete pycnidia with aseptate, cylindrical to ellipsoidal conidia with distinct hyaline sheath.

Type species.

Sheathospora cornuta (C.M. Tian & Z. Du) Fan.

Descriptions.

Conidiomata pycnidial, immersed in host bark, erumpent through the surface of host branches. Ectostromatic disc inconspicuous and ex tended to form a beak at maturity. Central column absent. Conidiophores hyaline, smooth, cylindrical, simple, rarely branched at the base. Conidiogenous cells hyaline, phialidic. Conidia hyaline, aseptate, with distinct hyaline sheath. Sexual morph was not observed.

Notes.

Sheathospora is established for Melanconiella cornuta , which was previously included in the Melanconiella clade ( Voglmayr et al. 2012; Du et al. 2017). Morphologically, it differs from other genera in Melanconiellaceae by pycnidial conidiomata and conidia with distinct hyaline sheath. In our phylogenetic analyses, Melanconiella cornuta formed a distinct clade basal to Melanconiella within Melanconiellaceae . Based on morphology and different hosts ( Cornus and Juglans vs. Betulaceae ), it is here excluded from Melanconiella and transferred to the new genus Sheathospora. In our revised circumscription, Melanconiellaceae include three genera named Melanconiella , Microascospora and Sheathospora .