Cadophora prunicola Damm & S.Bien, 2020

Bien, Steffen & Damm, Ulrike, 2020, Arboricolonus simplex gen. et sp. nov. and novelties in Cadophora, Minutiella and Proliferodiscus from Prunus wood in Germany, MycoKeys 63, pp. 119-161 : 119

Cadophora prunicola Damm & S.Bien sp. nov. Figures 5G, H , 12

Type.

South Africa, Western Cape province, Franschhoek, from reddish-brown necrosis in wood of Prunus salicina close to an old pruning wound, 10 June 2004, U. Damm leg., CBS H-19985 - holotype; GLM-F117487 - isotype; CBS 120891 = STE-U 6202 = GLMC 1902 - culture ex-type.

Etymology.

Named after its host genus, Prunus + suffix -cola (dweller).

Description.

Sexual morph not observed. Asexual morph on SNA. Vegetative mycelium hyaline, septation hardly visible, branched, 1-3 µm wide, sometimes becoming brown with age, chlamydospores absent, hyphae of strain GLMC 735 in some parts inflated and restricted at the septae and up to 5 µm wide. Sporulation abundant, conidia formed on hyphal cells. Conidiophores hyaline, simple or septate and branched, up to 50 µm long. Conidiogenous cells enteroblastic, hyaline, smooth-walled, cylindrical, often inflated and bent in the upper part or attenuated at the base, delicate (disintegrating quickly), 4-15 × 1.5-2 µm, in strains GLMC 735 and GLMC 1574 sometimes integrated, necks cylindrical, 3-3.5 × 1 µm, collarettes distinct, funnel-shaped, cylindrical, 1-3 µm long, 1-2 µm wide at the upper edge, opening 1-1.5 µm wide, periclinal thickening sometimes observed. Conidia aggregated in heads, hyaline, smooth-walled, aseptate, ellipsoidal, cylindrical to ovoidal, straight, rarely slightly curved, both ends rounded, (2.5-)3-6.5(-9) × 1.5-2 µm, mean ± SD = 4.9 ± 1.8 × 1.7 ± 0.3 µm, L/W ratio = 2.8, conidia of strain GLMC 1574 smaller, measuring (2.5-)3.5-5(-6.5) × 1.5-2.5(-3) µm, mean ± SD = 4.2 ± 0.7 × 1.4 ± 0.4 µm, L/W ratio = 2.1.

Culture characteristics.

Colonies on SNA (strains GLMC 735, GLMC 1574 and GLMC 1633) flat with an entire to undulate margin, whitish, lacking aerial mycelium, reverse same colours, 18-27 mm diam. in 2 wk (25 °C in the dark). Colonies on OA (strains GLMC 735, GLMC 1574 and GLMC 1633) flat with an entire margin to undulate margin, buff, very pale luteus to cinnamon, lacking aerial mycelium, except for strain GLMC 1574 that was partly covered by white woolly aerial mycelium, reverse buff to fawn, 20-27 mm diam. in 2 wk (25 °C in the dark). Colonies on PDA (CBS 120891) flat to raised, entire margin, mycelium and surface white to very pale smoke-grey, with age turning isabelline to olivaceous in the centre, abundant velvety aerial mycelium, reverse straw to pure yellow, 18 mm diam. in 2 wk (25 °C). Colonies on MEA (CBS 120891) raised with entire margin, mycelium and surface white to very pale luteous, with age turning isabelline, abundant velvety aerial mycelium, reverse buff, honey to salmon, in diffuse daylight with a concentric apricot ring between centre and margin, 24 mm diam. in 2 wk (25 °C).

Notes.

Cadophora prunicola was isolated from Prunus salicina (2) in the Western Cape Province of South Africa, from P. cerasus (3) and P. domestica (2) in Saxony and P. domestica (3) in Baden-Württemberg, Germany. The strains from South Africa, as well as three strains from both hosts from Saxony and two strains from Baden-Württemberg, were selected for the phylogenetic analyses. This species is similar to C. novi-eboraci and C. africana , but differs by forming conidiophores of up to 50 µm length and conidiogenous cells that are often inflated. Subglobose or tear-shaped conidia as in C. africana have not been observed. The ITS, TUB and EF-1α sequences of C. prunicola differ in 8, 29 and 9 nucleotides, respectively, from C. novi-eboraci and in 11, 30 and 20 nucleotides, respectively, from C. africana .

A blastn search with the ITS sequence of C. prunicola in GenBank showed a 100% identity with an uncultured Cadophora from dead wood of Fagus sylvatica in Germany (LC015696, Floren et al. 2015).

Additional material examined.

Germany, Saxony, orchard east of Lungkwitz, 50°56'12.4"N, 13°47'36.6"E, from brown wedge-shaped necrosis in wood of Prunus cerasus , 11 Aug 2015, S. Bien leg., GLM-F106569, culture GLMC 735 = CBS 145521 = DSM 109135; Baden-Württemberg, orchard west of Nussbach, 48°31'55.8"N, 8°00'52.4"E, from brown necrosis in wood of P. domestica , 23 Aug 2016, S. Bien leg., GLM-F110714, culture GLMC 1633 = CBS 145522 = DSM 109146; Baden-Württemberg, orchard east of Nussbach, 48°31'57.3"N, 8°01'49.6"E, from brown wedge-shaped necrosis in wood of P. domestica , 23 Aug 2016, S. Bien leg., GLM-F110654, culture GLMC 1574; South Africa, Western Cape province, Franschhoek, from necrosis in wood of P. salicina close to old pruning wound, 10 June 2004, U. Damm leg., STE-U 6103.

Figures

Figure 5. Colony surface of analysed strains on OA medium. A Arboricolonus simplex GLMC 459 T B Cadophora africana CBS 120890 T C C. bubakii CBS 198.30 T D C. luteo-olivacea GLMC 1264 E C. novi-eboraci GLMC 1472 F C. obscura CBS 269.33 G C. prunicola CBS 120891 T H C. prunicola GLMC 1633 I C. ramosa GLMC 377 T J Minutiella pruni-avium GLMC 1624 T K Proliferodiscus ingens GLMC 1751 T L Proliferodiscus sp. GLMC 460. Cultures A, J-L after 4 wk. Cultures B-I after 2 wk. Strains with a superscript T are ex-type cultures.

Figure 12. Cadophora prunicola sp. nov. A-G conidiophores and conidiogenous cells H conidia A-H from SNA A-H LM. Scale bar: 5 μm (A applies to B-H).