Trichoderma erinaceum Bissett, C.P. Kubicek & Szakács, Can. J. Bot. 81: 583 (2003)

Index Fungorum number: IF 488348

Saprobic on Baccaurea ramiflora. Sexual morph: Stromata scattered or aggregated in small numbers; pulvinate with circular or oblong outline when fresh, pale brown, ostiolar dots distinct, 0.2 mm high × 0.5–1 mm wide, narrowly attached, margin free, flat or convex, dark brown, surface smooth to slightly tubercular, white when young, pale brown with a reddish tinge or brown with a thin whitish to greyish covering, appearing grey-brown at maturity, often covered by white powdery spore mass; lower side white, papyraceous, not changing colour in 10% KOH, cortical layer 15–22.5 μm thick, comprising a light (yellow-) to brown, textura angularis of thin-walled cells. Subcortical tissue a loose textura intricata of hyaline, thin-walled hyphae. Sub-perithecial tissue consists of a mixture of textura angularis and textura epidermoidea cells, hyaline, partly pale brownish, thin-walled cells denser toward the base, often collapsing and entirely hyphal, periphysate, ostiolate. Perithecia 100–110 × 113–141 μm wide, crowded, globose to subglobose. Peridium 12.5 μm wide with few layers of textura angularis cells, yellow. Asci 8-spored or 16-part-spored, unitunicate, cylindrical. Ascospores 1.2–1.9 × 1.0–1.4 μm (x̅ = 1.5 × 1.2 μm, n = 25), obliquely biseriate, splitting into part spores, cells dimorphic, globose, oblong with 1–3 guttules, hyaline. Asexual morph: Undetermined.

Culture characteristics White colonies on malt extract agar, filamentous, sterile mycelium, reverse white, reaching 46 mm diam. in a week at 28 °C.

Material examined – India, Andaman and Nicobar Islands, North Andaman, Diglipur, Nabagram (13˚13’18.1”N 92˚55’59.3”E), found on decaying twig of Baccaurea ramiflora, 17 May 2018, M. Niranjan & V.V. Sarma (PUFNI 18730, AMH-10060), living culture, NFCC-4431; India, South Andaman, Port Blair, Wright Mayo (11˚47’39” N 92˚42’36”E), on Pterocarpus dalbergioides, 22 October 2015, (T38F5, T39F2, T52F2, isotypes); India, Mannarghat (11˚43’14” N 92˚39’33”E), on Pterocarpus dalbergioides, 04 January 2017, Niranjan. M & Sarma. V.V., T184F1, T193Fl.

GenBank accession numbers – ITS: MK990281, LSU: MK981537.

Known distribution (based on molecular data) – Bangladesh, Brazil, China, Colombia, India, Mexico, Nigeria, Papua New Guinea, Singapore, Taiwan, Thailand, South Korea, Sri Lanka, Pakistan, Peru, USA, Venezuela & Vietnam (https://www.ncbi.nlm.nih.gov/nuccore).

            Known hosts (based on molecular data) – Acanthaster planci, Atractylodes macrocephala, Baccaurea ramiflora, Cassia tora, Caulerpa scalpelliformis, Curcuma longa, Lygus lineolaris,  Pterocarpus dalbergioides, Theobroma cacao, Rhizosphere of Pomegranate, Coastal soil & Rhizosphere of chickpea (https://www.ncbi.nlm.nih.gov/nuccore).

Notes – Trichoderma is one of the most common genera in Ascomycota and consists of 100 species (Wijayawardene et al. 2018), and is characterized by superficial stromata, flat on the substrate, unitunicate asci, and eight ascospores that become partial spores when mature. Many new species have been introduced into this genus (Jaklitsch 2009, 2011, Qin & Zhuang 2016). The blastn search of sequences at NCBI showed that our isolate closely related to T. erinaceum, T. dingleyae, T. caribbaeum var. caribbaeum, and T. koningii with over 99% similarity. These species have slight differences among them; T. koningii has larger ascostromata and smaller ascospores than T. erinaceum. Trichoderma dingleyae has the largest ascostromata and perithecia.

Trichoderma erinaceum (NFCC-4431, new host record). a, b Stroma on host. c Vertical section. d Ascoma perithecia. e, f Asci. g, h Culture on MEA plates. Scale bars: c = 50 μm, c, d = 20 μm, d–f = 10 μm.