Scytalidium album L. Beyer & Klingström

1. Scytalidium album L. Beyer & Klingström View in CoL , Svensk bot. Tidskr. 59: 35 (1965)

Description and illustration.

Klingström and Beyer (1965).

Notes.

Scytalidium album was initially isolated from Norway spruce wood damaged by root rot, and it induces blue staining in timber ( Klingström and Beyer 1965). Scytalidium album is phylogenetically closely related to S. assmuthi , S. aurantiacum , S. rodionovae , S. circinatum , S. terrigenum , and S. tongrenense (Figs 1 View Figure 1 , 2 View Figure 2 ). Morphologically, S. album is distinguished from S. assmuthi , S. rodionovae , and S. tongrenense by its unknown sexual morph and simultaneous production of arthroconidia and chlamydospore-like cells ( Klingström and Beyer 1965; Pavlov et al. 2018; Manawasinghe et al. 2024). Scytalidium album differs from S. terrigenum by its hyaline arthroconidia ( Jeong et al. 2025) and from S. circinatum by the shape and size of its chlamydospore-like cells (globose or ellipsoidal, 6.4–14.4 × 4.8–9.6 μm in S. album vs. globose, lobed, or irregular, 4–9 × 3–9 μm in S. circinatum ) ( Sigler and Wang 1990). Furthermore, S. album differs from S. aurantiacum by its secretion of a pale-yellow pigment ( Klingström and Beyer 1965). Additionally, they can be distinguished by their low sequence similarities. Based on a pairwise comparison of ITS and LSU, S. album (ex-type CBS 372.65 ) differs from S. assmuthi (ex-type PYCC 9837 ) by 7.4 % (34 / 460 bp, four gaps) in the ITS and 4.2 % (23 / 536 bp, one gap) in the LSU; from S. aurantiacum (ex-type CBS 374.65 ) by 2.9 % (15 / 521 bp, no gap) in the ITS and 2.5 % (14 / 553 bp, no gap) in the LSU; from S. rodionovae (ex-type 3 C) by 8.6 % (49 / 571 bp, five gaps) in the ITS and 3.7 % (22 / 591 bp, no gap) in the LSU; from S. circinatum (ex-type CBS 654.89 ) by 6.8 % (49 / 721 bp, five gaps) in the ITS and 5.4 % (67 / 1,234 bp, five gaps) in the LSU; from S. terrigenum (ex-type KNUF- 23-236) by 3.9 % (23 / 580 bp, one gap) in the ITS and 3.3 % (19 / 561 bp, four gaps) in the LSU; and from S. tongrenense (ex-type CGMCC 3.28994 ) by 6.6 % (36 / 544 bp, six gaps) in the ITS and 2.4 % (14 / 575 bp, one gap) in the LSU.

This species demonstrates notable inhibitory effects against various wood-decay fungi, revealing promising biocontrol potential ( Klingström and Beyer 1965; Klingstrom and Johansson 1973; Cease et al. 1989). Furthermore, it produces diverse, unique metabolites (such as sorbicillinoid analogs) that exhibit significant inhibitory activity against cancer cells and Aspergillus niger , indicating considerable medicinal potential ( El-Elimat et al. 2015).