Diaporthe sennicola C.M. Tian & Q. Yang, 2017

Yang, Qin, Fan, Xin-Lei, Du, Zhuo & Tian, Cheng-Ming, 2017, Diaporthe species occurring on Senna bicapsularis in southern China, with descriptions of two new species, Phytotaxa 302 (2), pp. 145-155 : 150-151

Diaporthe sennicola C.M. Tian & Q. Yang , sp. nov. FIGURE 3 .

MycoBank no: MB 820453

Holotype:— BJFC-S1368 .

Etymology:— sennicola , named after the genus of the host, Senna .

Host/Distribution:—from Senna bicapsularis in southern China.

Original description:—Sexual morph: undetermined. Asexual morph: Conidiomata pycnidial, immersed, scattered, slightly erumpent through the bark surface, circular to ovoid, with a single locule. Ectostromatic disc dark brown, nearly flat, ovoid. Locule undivided, (300–)345–400(−435) μm (av. = 390 μm, n = 20) in diam. Conidiophores hyaline, branched, phialidic, straight or slightly curved, tapering towards the apex, (9.0–)11.0–14.5(−16.0) × (0.9–)1.1−1.4 μm (av. = 12.5 × 1.2 μm, n = 50). Conidiogenous cells hyaline, phialides, straight or slightly curved. Alpha conidia hyaline, aseptate, ellipsoidal, conspicuously biguttulate, (5.6–)6.0–7.2(−7.6) × 2.4–3.1(3.4) μm (av. = 6.7 × 2.8 μm, n = 50). Beta conidia absent.

Culture characters:—Cultures incubated on PDA at 25° C in darkness, colony originally flat with white felty aerial mycelium, becoming white compact furcate mycelium at the centre and auburn furcate mycelium at the marginal area, with irregular margin, conidiomata sparse, irregularly distributed over agar surface.

Material examined:— CHINA, Guangxi Province: Nanning City, 21°47’31.46”N, 118°23’13.25”E, 216 m asl, on twigs and branches of Senna bicapsularis, Q. Yang , 7 November 2015 ( BJFC-S 1368, holotype; ex-type culture, CFCC 51634). Guangxi Province: Nanning City, 21°47’31.46”N, 118°23’13.25”E, 216 m asl, on twigs and branches of Senna bicapsularis, Q. Yang , 7 November 2015 ( BJFC-S 1369, paratype; living culture, CFCC 51635).

Notes:—This new species is introduced as molecular data show it to be distinct clade with high support ( MP / ML / BI =100/100/1). In the phylogenetic tree ( Fig. 1 ), D. sennicola is mostly related to D. apiculata Y.H. Gao & L. Cai from Camellia sinennsis , D. gardeniae (Buddin & Wakef.) R.R. Gomes, C. Glienke & Crous from Gardenia florida and D. charlesworthii R.G. Shivas, S.M. Thomps. & Y.P. Tan from Rapistrum rugosum ( Fig. 1 ). In morphology, D. sennicola differs from D. apiculata in its narrower conidiophores and shorter alpha conidia (conidiophores: 1.1−1.4 μm in D. sennicola vs. 1.5−2.5 μm in D. apiculata ; alpha conidia: 6.0–7.2 μm in D. sennicola vs. 6.5–10.0 μm in D. apiculata ) ( Gao et al. 2016). Diaporthe gardeniae was originally observed in 1894 in England ( Cooke 1894) and has since been reported from the USA and India ( Preston 1945, Mathur 1979). Gomes et al. (2013) provided DNA data for this species using the strain, CBS 288.56, from Gardenia florida in Italy. But there are no illustrations and detailed descriptions. D. sennicola differs from D. charlesworthii in its shorter conidiophores and alpha conidia (conidiophores: 11.0−14.5 μm in D. sennicola vs. 15−35 μm in D. charlesworthii ; alpha conidia: 6.0–7.2 μm in D. sennicola vs. 7–9.5 μm in D. charlesworthii ) ( Thompson et al. 2015).

Figures

FIGURE 1. Phylogram of Diaporthe based on combined ITS, CAL, HIS, TEF1-α and TUB. MP and ML bootstrap support values above 50 % are shown at the first and second position. Thickened branches represent posterior probabilities above 0.90 from BI. Scale bar = 90 nucleotide substitutions. Ex-type strains are in bold. Strains in current study are in blue.

FIGURE 3. Morphology of Diaporthe sennicola from Senna bicapsularis (BJFC-S1368).A: Habit of conidiomata on twig. B: Transverse sections through conidiomata. C: Longitudinal sections through conidiomata. D: Colonies on PDA at 3 days (left) and 30 days (right). E: Alpha conidia. F: Conidiophores. Scale bars: B–C = 200 μm; E–F = 5 μm.