Melansporella juglandium C.M. Tian & Z. Du, 2017

Du, Zhuo, Hyde, Kevin D., Yang, Qin, Liang, Ying-Mei & Tian, Cheng-Ming, 2017, Melansporellaceae: a novel family of Diaporthales (Ascomycota), Phytotaxa 305 (3), pp. 191-200 : 197

Melansporella juglandium C.M. Tian & Z. Du , sp. nov. ( Fig. 2 ) MycoBank MB820307

Etymology:— juglandium , referring to Juglans regia , the only host known for this species.

Holotype:— BJFC-S1374 .

Host/Distribution:— from Juglans regia in China.

Description:— Pustules on bark of cankered or dead stems and twigs. Ascostroma immersed, slightly erumpent from surface of host branches, conical, (1.5–)2–2.5(–3) mm (av. = 2.5 mm, n = 20) in diam. Perithecia globular to subglobular (430–)550–700(–800) μm (av. = 580 μm, n = 20) in diam., long black necks (500–)600–850(–950) μm (av. = 825 μm, n = 20), clustered beneath the disc at the top. Asci (120–)122–135 × (12.5–)13–16.5 (–17) μm (av. = 126.5 × 15 μm, n = 20), oblong or fusoid, 8-spored. Ascospores irregularly uniseriate, fusoid, 2-celled, hyaline, (17–)17.5–22(– 23.5) × (7.5–)8–10.5(–11) μm (av. = 19.5 × 9.5 μm, n = 50). Pycnidial stroma black, conspicuous, with a single locule, 1.5–2(–2.5) mm (av. = 2 mm, n = 20) diam. Ectostromatic disc saffron to black. Conidiophores cylindrical, hyaline to light brown, simple, formed at the conidiomatal wall, (24–)28–52(–60) μm (av. = 43 μm, n=20) long. Conidiogenous cells subcylindrical to cylindrical, smooth-walled, produce conidia acrogenously. Conidia ovoid, with distinct hyaline sheath, brown to dark brown, unicellular, surface structures, (21–)21.5–26(–26.5) × (12–)13–15.5(–16) μm (av. = 24 × 14 μm, n = 50).

Culture characterisctics:— Culture growth on PDA is initially white, becoming yellowish after 3–5 days. The colony is flat, with an irregular edge, texture uniform, producing dark green to black pigment after 7–10 days. Conidiomata sparse, irregularly distributed over agar surface, black mucous conidia were produced on the colony.

Material examined:— CHINA. Heilongjiang Province: Harbin City: Heilongjiang Botanical Garden, 45°42’21.10”N, 126°38’42.87”E, 128 m asl, on twigs and branches of Juglans regia , coll. Z. Du & Q. Yang, 2 Aug 2016 ( BJFC-S 1374, holotype), ex-holotype living culture, CFCC 51725).

Additional materials examined:— CHINA. Gansu Province: Qingyang City, Shenshe Town, 35°38’17.08”N, 107°47’48.68”E, 1253m asl, on twigs and branches of Juglans regia , coll. X. L. Fan, 14 Jul 2013 ( BJFC-S 908, living culture, CFCC 51727). CHINA. Gansu Province: Qingyang City, Zhongwan Forest Centre, 35°26’26.33”N, 108°34’09.38”E, 1553m asl, on twigs and branches of J. regia , coll. X. L. Fan, 11 Jul 2013 ( BJFC-S 947, living culture, CFCC 51728). CHINA. Gansu Province: Qingyang City, Zhongwan Forest Centre, 35°26’25.52”N, 108°34’09.03”E, 1580m asl, on twigs and branches of J. regia , coll. X. L. Fan, 11 Jul 2013 ( BJFC-S 955, living culture, CFCC 51729).

Notes:— Melansporella juglandium is the type species of Melansporella , and only occurs on Juglans regia . Isolates were identified as Melansporella juglandium based on holomorphic morphology characters, host, and high support in the phylogeny ( MP / ML / BI =100/96/1). Hence, we treat this taxon as a novel species of Melansporella .

Figures

FIGURE 2. A. Habit of ascostroma and conidiomata on twig. B, C. Habit of conidiomata on twig. D. Transverse section through a conidioma. E, I, J. Longitudinal section through conidiomata. F–H. Habit of ascomata on twig. K, L. Conidiophores and conidia. M, N. Conidia. O, P. Asci and ascospores. Q, R. Ascospores. Scale bars:A = 5 mm, B–G, J = 500 μm, H, I = 1 mm, K–R = 20 μm.