Poculum pseudosydowianum, Hosoya & Zhao & Degawa, 2014

Hosoya, Tsuyoshi, Zhao, Yan-Jie & Degawa, Yousuke, 2014, Poculum pseudosydowianum, sp. nov. (Rutstroemiaceae, Ascomycota) from Japan and its endophytic occurrence, Phytotaxa 175 (4), pp. 216-224 : 219-222

Poculum pseudosydowianum Y.-J. Zhao & Hosoya sp. nov. ( Figs. 3–5 )

MyxoBank no:— MB 807590

Holotype:— Japan: Nagano Pref., Ueda City, Sugadaira Montane Research Center, University of Tsukuba , 36º31’30.00”N, 138º20’51.20”E, elev. 1349 m, 28 Sep. 2011, Col. Y.- J. Zhao, TNS-F-40071! (Culture NBRC 109870 =FC-2813), on petioles of Q. crispula .

Distribution and habitat:— Japan, collected from the decayed leaves and petioles of Quercus crispula and Q. serrata , in particular Q. crispula .

Etymology:— referred to its morphological resemblance to the closely related species P. sydowianum

Additional specimens examined:— On petioles of Quercus crispula :— Nishikionuma Park, Tomakomai-shi , Hokkaido, 42º36’39.60”N, 141º27’10.00”E, elev. 27 m, 12 Sep. 2011, Col. Y.- J. Zhao, TNS-F-40039; Green tunnel, Tomakomai-shi, Hokkaido Pref. 42º43’22.18”N, 141º33’59.89”E, elev. 92 m, 13 Sep. 2011, Col. T. Hosoya, TNS-F- 42316 (Culture FC-2766); Tomakomai Experimental Forest , Hokkaido University, Tomakomai-shi, Hokkaido Pref., 42º40’21.70”N, 141º36’26.60”E, elev. 22 m, 15 Sep. 2011, Col. Y.- J. Zhao, TNS-F-40059; Takayama-mura, Gunma Pref., 36º35’19.3”N, 138º57’36.5”E, elev. 242 m, 2 Oct. 2012, Col. Y.- J. Zhao, TNS-F-40165 ;

On petioles and branches of unidentified plant:— Niigata Pref., Japan, 37º0’56”N, 138º46’54.7”E, elev. 846 m, 3 Oct. 2012, Col. Y.- J. Zhao, TNS-F-40172 .

On petioles of Quercus serrata :— Takayama-mura , Gunma Pref. (36º35’19.3”N, 138º57’36.5”E, elev. 242 m), 2 Oct. 2012, Col. Y.- J. Zhao, TNS-F-40163 (FC-5091) .

Description:—Stroma substratal, visible on petioles as clear, irregular, black lines delimiting blackened zones. Apothecia stipitate, occurring on decaying petioles; disc flat to cupulate when fresh, becoming concave when dry, leathery, 0.6–1.7mm in diameter; hymenium pale brownish yellow (1365 PC= C0 M33 Y75 k0) when fresh, becoming dark reddish brown to dark brown (175PC= C18 M79 Y71 K56) when dry; receptacle slightly paler than the hymenium when fresh, furfuraceous, with reddish brown, longitudinal striation running along the longitudinal direction on the surface; stipe subcylindric, concolorous with the receptacle, 1–3.4 mm long when dry, becoming much darker toward base. Ectal excipulum three layered: the outermost covering layer 5–10 μm thick, composed of thin walled, septate, pale brownish hyphae of 2–4 μm width; outer ectal excipulum 25–40 μm thick, colorless, gelatinous, highly refractive, composed of very thick-walled, interwoven hyphae almost running in parallel; inner layer thin-walled, pale brown hyphae of 5–8 μm wide. Medullary excipulum textura intricata, composed of loosely interwoven, pale brown hyphae of 3–5 μm wide. Asci 82.5–100×7.5–12.5 μm (90.8 ± 4.4×10.3± 1.1 μm on average ± SD, n= 25), clavate, 8-spored, arising from croziers; apex truncate, 4–5 μm thick; pore stained blue by Melzer’s reagent with or without 3% KOH pretreatment. Ascospores 10–13.8×5–6.3 μm (12.5 ± 1.1×5.3± 0.5 μm on average ± SD, n= 25), uniseriate, broadly obovoid-reniform, straight to strongly curved, smooth, some with a large guttule at the center; becoming 1–3 septate, pale brown to brown, with cell walls becoming slightly thickened and darker when germinated on PDA. Paraphyses straight, septate, hyaline, slightly enlarged at the apex to 2–4 μm.

Cultural characteristics:— Colonies on PDA grows fast, covering the whole plate after 4 weeks incubation; surface floccose, whitish to grayish with aerial mycelium which is white, cottony, fully developed, partially black due to the development of melanized hyphal aggregation; margin entire; reverse uncolored to pale brown. Apparent black line formation not observed in culture. Spermatia hyaline, produced singly or successively from small tubes at one end of ascospore when ascospores germinated; on PDA, spermatia produced abundantly from phialidic spermatiophores, broadly ellipsoid to subglobose, 2–3.2× 1.8–3.3μm.

Figures

FIGURE 3. Poculum pseudosydowianum (TNS-F-40039). A: Fresh apothecia on Quercus crispula petioles. B: Close up of rind in substrate. C: Vertical section of ectal excipulum. D: Close up of ectal excipulum at the margin. E: Brown striation in receptacle. F: Close up of brown striation formed by pigmented hyphae. G: Asci. H: Reaction of ascal apex to MLZ. I: Paraphyses. J. Croziers in the base of asci. K. Hyaline ascospores. L. Germinating ascospores. Bars B, E 1mm; C 100 μm; D, F–L 20 μm.

FIGURE 4. Camera lucida illustration of Poculum pseudosydowianum (TNS-F-40039). A: Asci. B: Reaction of ascal apex to MLZ. C: Paraphyses. D: Vertical section of an apothecium through the margin showing the ectal excipulum. E: Ascospores, the bottom shows the germinated ascospores. F: Vertical section of ectal excipulum. Bars A–E 10 μm; F 20 μm

FIGURE 5. Cultural characters of Poculum pseudosydowianum (FC-2813, Culture of TNS-F-40071). A: Colony on PDA (20°C, 1 mo.). B: Colony on PDA (20°C, 3 mo.). C: Spermatia produced in 3 mo.’ PDA. D: Spermatia and spermatiophores. E: Spermatia produced in germinated ascospores. Bars C–E 20μm.