Monochaetia ilexae N.I. de Silva, Phookamsak & K.D. Hyde, 2017

De Silva, Nimali I., Phookamsak, Rungtiwa, Maharachchikumbura, Sajeewa S. N., Thambugala, Kasun M., Bhat, Darbhe J., Al-Sadi, Abdullah M., Lumyong, Saisamorn & Hyde, Kevin D., 2017, Monochaetia ilexae sp. nov. (Pestalotiopsidaceae) from Yunnan Province in China, Phytotaxa 291 (2), pp. 123-132 : 126

Monochaetia ilexae N.I. de Silva, Phookamsak & K.D. Hyde , sp. nov.

Index Fungorum number: IF552505, Faces of Fungi number: FoF 02622

Etymology: the epithet “ ilexae ” refers to the host, of which the taxon was collected.

Saprobic on dead leaves of Ilex sp. Sexual morph: Undetermined. Asexual morph: Conidiomata 115–180 μm diam, pycnidial, solitary, scattered, immersed to erumpent, easily broken, visible as brown, flat, scar-like structures on the host, uni-loculate, glabrous, without an ostiole, releasing conidia by breaking the host surface. Conidiomata wall multi-layered, thin walled, brown, comprising cells of textura angularis. Conidiophores indistinct. Conidiogenous cells 4–6 × 1–2 μm (x =5.4 × 1.4 μm), holoblastic, phialidic, discrete, cylindrical, hyaline, smooth, thin-walled. Conidia 20–27 × 3–5 μm diam. (x =23.7 × 6 μm), fusiform, tapering at both ends, 4-septate, erect or sometimes slightly curved; apical cell 2.5–4.7 μm long (x =3.7 μm), conical, hyaline and smooth-walled; three median cells together 13–18 μm long (x =15.8 μm), doliiform, brown, rough-walled, echinulate, upper second cell 4.9–7.1 μm long (x =5.7 μm), upper third cell 3.5–5.9 μm long (x =5.1 μm), upper fourth cell 4.3–6.9 μm long (x =5.6 μm); basal cell 2.6–5.2 μm long (x =3.7 μm), conic, hyaline and smooth-walled; apical appendage 6–24 μm long (x =15.3 μm), single, tubular, filiform; basal appendage 3–12 μm long (x =7.3 μm), single, central, tubular, filiform.

Culture characteristics: Colonies on PDA 35 mm diameter after 7 days at 25 °C, circular, raised, dense surface with lobate edge, zonate with different sector light brown at the margin, brown at the center and; reverse brown at the margin, dark brown at the center.

Material examined: CHINA, Yunnan Province, Shangri-La, on a dead leaf of Ilex sp. (Aquifeliaceae), July 2014, R. Phookamsak, NI009 (HKAS 92492, holotype, MFLU 16–1429 isotype), ex-type living culture KUMCC 15–0520, MFLUCC 16–0829.

Notes: The new strain, Monochaetia ilexae clusters with Monochaetia species, but is separated from the main clade with high bootstrap support (100% ML, 98% MP, 1.00 PP, Fig. 1 ). Monochaetia ilexae shares similar morphology with the type, M. monochaeta ( Guba 1961) in having fusiform conidia and has a similar range of conidia (20–27 μm) with M. kansensis (18–26 μm) ( Guba 1961). However, M. ilexae differs from M. monochaeta as the former has fusiform, brown, 20–27 μm long conidia with a 6–24 μm long, single, apical appendage, whereas M. monochaeta has pale olivaceous, 15–21 μm long conidia, with a 5–19 μm long, single, apical appendage ( Guba 1961). Monochaetia kansensis differs in its erect, slightly curved, olivaceous or umber conidia, with a 10–38 μm long, single, apical appendage.

In Table 2 we tabulate the morphological data for different Monochaetia species ( Guba 1961). Monochaetia species have been recorded from range of host species, including Alnus sp. , Bellota sp. , Camellia sp. , Castanea sp. , Corylus sp. , Cryptomeria sp. , Osyris sp. , Pteridium sp. , Quercus sp. , Rosa sp. , Russelia sp. , Schinus sp , ( Guba 1961) and this is the first record from Ilex sp. in China ( Guba 1961, Farr & Rossman 2016).

Monochaetia bicornis , M. hysteriiformis , M. macropoda , M. miersii , M. monochaeta , M. osyrella and M. osyridella have fusiform conidia, which are similar to those of M. ilexae . Among them, M. hysteriiformis and M. osyridella have overlapping conidial lengths with M. ilexae . However, M. hysteriiformis has umber-coloured conidia, with 19–24 μm median cells and M. osyridella has chestnut brown conidia, with 15–18 μm long, basal appendage, that differs from M. illexae . Monochaetia alnea , M. cryptomeriae , M. kansensis , M. phyllostictea , M. rosae-caninae and M. schini do not have fusiform conidia.

Figures

FIGURE 1. Phylogenetic tree resulting from maximum likelihood analysis of the combined LSU and ITS sequence alignment. Bootstrap values for maximum likelihood (ML, black) and maximum parsimony (MP, red) are shown at the nodes (ML/MP). Bayesian posterior probabilities, greater than 0.90 are indicated by thickened lines. The tree is rooted with Bartalinia robillardoides (CBS 122705). The new strain is indicated in red bold and type strains are indicated as black bold.