Stachybotrys microsporus (B. L. Mathur & Sankhla) S. C. Jong & E. E. Davis

Stachybotrys microsporus (B. L. Mathur & Sankhla) S. C. Jong & E. E. Davis View in CoL [as ‘ microspora’]

Fig. 6 View Figure 6

Description.

Saprobic on dead leaf of Agave sisalana . Sexual morph: undetermined. Asexual morph: Colonies superficial on host substrate, gregarious, visible as numerous black conidial masses. Conidiophores 35–70 × 2.5–5 µm (av. 48 × 4 μm, n = 30), macronematous, mononematous, irregularly or sympodially branched, straight or flexuous, subcylindrical, hyaline, becoming pale olivaceous brown in the above half, 1–3 - septate, not constricted at the septa, smooth-walled, slightly rough-walled in the subterminal region, thick-walled, bearing 3–9 conidiogenous cells on the tip. Conidiogenous cells 6–10 × 4–6 µm (av. 8 × 5 μm, n = 30), enteroblastic, monophialidic, discrete, determinate, terminal, obovoid, sub-hyaline to pale olivaceous brown, smooth-walled. Conidia 5–7 µm diam. (av. 6 μm, n = 30), aggregating in slimy masses, globose, subglobose, aseptate, olivaceous brown to black, rough-walled, verrucose.

Culture characteristics.

Colonies on PDA reaching 2.5–3.0 cm in two weeks at 28 ± 2 ° C, medium dense, raised, flat, floccose to fluffy, velvety, irregular edge, gold brown at the center, pale brown, with conidiophores forming on the surface of the medium, carrying slimy olivaceous green from above; brown to pale luteous from the reverse. The conidia producing on PDA after three weeks: Conidiophores 30–80 × 3.5–5.5 µm (av. 46 × 4 μm, n = 30), most similar with the above description, 0–2 - septate, unbranched or branched, bearing 2–10 conidiogenous cells at the tip. Conidiogenous cells 9–17 × 4.5–7.5 µm (av. 12 × 5.5 μm, n = 30), most similar to those on natural substrate. Conidia 6.5–10 × 3–6.5 µm (av. 8 × 5 μm, n = 30), often aggregated as large, slimy, glistening, blackheads, initially hyaline to olivaceous green, oblong, obovoid to subglobose, becoming black-brown, globose, smooth to verruculose.

Material examined.

China • Guangdong Province, Guangzhou City, Zhongkai University of Agriculture and Engineering (23.10643 ° N, 113.28240 ° E, 20 m), on dead leaf of Agave sisalana Perr. ex Engelm. ( Agavaceae ), 17 November 2021, C. F. Liao & Y. H. Yang, SR 09 A ( MHZU 23-0252 , new host record) • living culture, ZHKUCC 23-1007 GoogleMaps • ibid., living culture ZHKUCC 23-1008 GoogleMaps .

Known distribution.

• Canada, Cuba, India, Nigeria, and Pakistan ( Ellis 1971; Jong and Davis 1976); • China (this study); Japan ( Iwama et al. 2022); • New Guinea; Zaria ( Jong and Davis 1976); • Thailand ( Lin et al. 2016; Samarakoon et al. 2021); • Sudan ( Lombard et al. 2016).

Known hosts / substrates.

Agave sisalana (this study), Arachishypogaea rhizosphere, soil ( Jong and Davis 1976), Castanopsis cuspidata var. sieboldii ( Iwama et al. 2022) , dead plants, paper, seeds, and textiles ( Ellis 1971), decaying shrubs, wood ( Lin et al. 2016), Musa sp. ( Samarakoon et al. 2021), soil in Mangifera field ( Lombard et al. 2016).

Notes.

Stachybotrys microsporus ( ZHKUCC 23-1007 , ZHKUCC 23-1008 ) formed a subclade with the type and other strains of St. microsporus with 100 % ML and 1.00 BYPP (Fig. 1 View Figure 1 ). Our collection has similar morphs to St. microsporus described by Jong and Davis (1976), Lin et al. (2016), and Samarakoon et al. (2021) by having irregularly branched conidiophores with tapering apices, monophialidic, discrete conidiogenous cells, unicellular, globose, roughened, and black conidia. Stachybotrys microsporus has been reported from forest soil in New Guinea ( Jong and Davis 1976), on decaying wood in Thailand ( Jong and Davis 1976), and on dead leaf petiole of Musa sp. in Thailand ( Samarakoon et al. 2021). We report St. microsporus here as a new host record on Agave sisalana in China.