Murinectria M. Niranjan & V.V. Sarma, gen. nov.

MycoBank number: MB 556843; Index Fungorum number: IF 556843; Facesoffungi number: FoF 06587; 4 species with sequence data.

Etymology – The generic name refers to Nectria spp. having muriform ascospores.

Sexual morph: Stromata immersed to erumpent, subiculate, solitary to aggregated, bright red. Ascomata perithecial, superficial, globose, gregarious, immersed in the stroma, KOH+ve pigments, often associated with synnemata of the asexual state. Peridium consists of cells of textura globulosa and textura angularis, walls pigmented. Asci unitunicate, 8-spored, cylindric-clavate, with or without an inconspicuous ring at apex, early deliquescent. Ascospores overlapping biseriate, hyaline to pale brown, yellow in Lugol’s solution, ellipsoidal to fusiform, muriform, often constricted at each septum, straight or slightly curved. Asexual morph: Synnematous on natural substrata, laterally oriented near perithecial ascomata, usually erumpent through epidermis, solitary to gregarious around ascomata, erect or nodding, red-brown at base, becoming dark brown to black with age, Conidiogenous cells phialidic. Conidia hyaline, obovoid, slightly flat to rounded apex, narrow towards base, acute or obtuse ends.

Type speciesMurinectria murispora M. Niranjan & V.V. Sarma.

NotesMurinectria is characterized by muriform ascospores, which are similar to some muriform species in Nectria. In our phylogenetic analysis, M. murispora branched separately from other species of Nectria but clustered closely with Nectria species with muriform ascospores. Hence, we establish a new genus Murinectria based on muriform ascospores in the sexual morph and a synnematous asexual morph with phialospores.

Table 1 List of the Murinectria species having muriform ascospores.

FungiAscomataAsciAscosporesSeptation
Murinectria315–548 μm high95–125 × 15–(19.4–)23.0–5–8 transverse septa
antarctica× 270–520 μm25 μm30.4(–35.1) ×and 1–2
diam(6.8–)8.1–10.9(–longitudinal septum,
13.6) μmnot constricted at
each septum
M. polythalama300–435 μm high70–96 × 15.7–(17.9–)21.8–5–8 transverse
× 290–345 μm17.9 μm29.0(–35.4) ×septate and 1–2
diam(6.1–)7.3–10.1(–longitudinal septate,
12.3) μm,often constricted at
each septum
M. pseudotrichia333–548 μm high65–125 × 13–(14.8–)21.0–5–8 transverse septa
× 296–534 μm32 μm28.8(–41.3) ×and 1-2 longitudinal
diam(4.6–)7.5–11.4(–septum, often
15.0) μmconstricted
M. murispora550–580 μm high70–96 × 14.5–(25.0–)26.1–5–9 transverse
× 415–500 μm18 μm36.6(–38.3) ×septate and 1–2 (–5)
diam(9.7–)10.2–16.3longitudinal septate,
(–18.6) μm,often constricted at
each septum