Chaenothecopsis neocaledonica J. Rikkinen, H. Tuovila & A.R. Schmidt, 2014

Rikkinen, Jouko, Tuovila, Hanna, Beimforde, Christina, Seyfullah, Leyla J., Perrichot, Vincent & Schmidt, Alexander R., 2014, Chaenothecopsis neocaledonica sp. nov.: The first resinicolous mycocalicioid fungus from an araucarian conifer, Phytotaxa 173 (1), pp. 49-60 : 52

Chaenothecopsis neocaledonica J. Rikkinen, H. Tuovila & A.R. Schmidt , sp. nov. ( Figures 2C and 3–5 )

Type: –– NEW CALEDONIA, Province Sud: Yaté. Along road RP 3 about 5 km west of Yaté. On resin, resin-soaked bark and lignum of Agathis ovata , 411 m, 22°10’03.63’’S, 166°54’10.15’’E, 5 November 2011, Rikkinen 010179 (holotype P, isotypes H, GenBank KF815196 / KF815197 , MycoBank MB 806059) .

Diagnosis:–– Chaenothecopsis neocaledonica differs from related Chaenothecopsis species in having very robust ascomata with wide and flat capitula, wide and thick-walled hyphae in the stipe, and noticeably large one-septate ascospores.

Description:–– Apothecia on exudate of Agathis ovata, 1400 –2400 µm high. Stipe shining black or sometimes olivaceous, straight, sometimes flexuous, occasionally branched, 180–260 µm wide. Capitulum black, in young apothecia usually lenticular to subspheric, later lobate and plano-concave, 150–600 µm wide. Asci cylindrical, 96–115 × 5.5–6.5 µm (n = 10), apex variously thickened, thickening gradually disappearing, mature asci usually without a thickening, apices often covered with hyaline, amorphous material IKI+ weakly blue, dissolving in KOH; formed with croziers. Ascospores uniseriate, usually obliquely to periclinally oriented in asci, septate, septa as thick or slightly thinner than spore wall, brown, ellipsoid to cylindrical, smooth, sometimes thickened at the ends; (12.3–) 13.4–17.6 (–18.6) × (4.4–) 4.9–6.3 (–6.7) µm (n = 100, from 7 ascocarps, 2 populations), mean 15.1 × 5.7 µm, Q = (2.2–) 2.3–3.1 (–3.8), mean Q = 2.7. Paraphyses hyaline, filiform, 1.0–1.5 µm wide (n = 10), with several branches, very long, reaching and curving above asci; septate, septal intervals 10–25 µm. Stipe hyphae covered with hard glass-like layer dissolving in KOH, 10–16 µm wide, walls two layered: outer wall hyaline, 2–5 µm wide, inner wall yellowish green to yellowish brown to dark brown, 1.5 µm wide; hyphae intertwined and outer cell walls fused (textura intricata-oblita); IKI+ slowly violet red; hyphae swell in KOH and brown pigment leaks into the medium; hyphae in inner part of stipe hyaline, slightly intertwined, walls up to 8 µm wide. Excipulum hyphae yellowish brown to greenish brown, 5–8 µm wide, wall 1–1.5 µm, periclinally arranged or slightly intertwined, outer cell walls fused (textura prismatica-oblita); IKI+ slowly violet red, hyphae swell in KOH, some brown pigment leaks into the medium. Hymenium IKI+ blue, slowly disappearing; full of colorless, CR– crystals, only partly dissolving in KOH. Hypothecium hyaline, hyphae swell in KOH. Epithecium yellowish green or almost hyaline, composed of elements from excipulum and paraphyses. The thick-walled hyphae of excipulum reach to cover the asci, intertwine and form a tight net, hard to break, with small holes, on average 3–5 × 5–8 µm in size. Paraphyses curve at the level of ascus tips to cover the asci, branch repeatedly just beneath the net of excipular hyphae, forming an inner layer of the epithecium; excipular part of epitechium IKI+ faint violet red. All parts MLZ –.

Etymology:—In reference to New Caledonia, France, where the species was first discovered.

Further specimens examined:–– NEW CALEDONIA, Province Sud: Yaté. Another Agathis ovata trunk at type locality, Rikkinen 010180 (paratype H). Along road GR NC 1 in Blue River Provincial Park near the Refuge des Scientifiques , 180 m, 22º05’58.62’’S, 166º39’00.12’’E, 12. November 2011, Rikkinen 010273 .

Figures

FIGURE 2. Habitat of Chaenothecopsis neocaledonica in southeastern New Caledonia. (A) Collecting specimens from a trunk of Agathis ovata in Blue River Provincial Park. (B) Large Agathis ovata tree west of Yaté which hosted the holotype specimen. (C) Ascomata of C. neocaledonica growing on a semi-solidified resin flow. Several termite fecal pellets are visible on the right.

FIGURE 3. Light micrographs of Chaenothecopsis neocaledonica (holotype, Rikkinen 010179). (A–F) Ascomata. (G–H) Ascospores. Scale bars = 100 μm (A–F) and 5 μm (G, H).

FIGURE 4. SEM micrographs of Chaenothecopsis neocaledonica (holotype, Rikkinen 010179). (A) Excipulum of young ascoma. (B– C) Thickened epithecium of mature ascoma. (D) Stipe surface. (E) Branch initial at base of mature stipe. (F–G) Ascospores. (H) Spore ornamentation. Scale bars = 20 μm (A–E) and 2 μm (F–H).

FIGURE 5. Line drawings of anatomical details of Chaenothecopsis neocaledonica (holotype, Rikkinen 010179 A–D, F–G; Rikkinen 010180 A, E) in water and CR. (A)Ascospores, (B) variation of ascus tip, (C) double layered structure of epithecium, (D) details of hyphae in the stipe, (E) general structure of stipe, (F) structure of excipulum, (G) asci and paraphyses.All scale bars 10 μm.