Paraeutypella citricola L.S. Dissan., Wijayaw., J.C. Kang & K.D. Hyde, 2021

Dissanayake, Lakmali S., Wijayawardene, Nalin N., Dayarathne, Monika C., Samarakoon, Milan C., Dai, Dong-Qin, Hyde, Kevin D. & Kang, Ji-Chuan, 2021, Paraeutypella guizhouensis gen. et sp. nov. and Diatrypella longiasca sp. nov. (Diatrypaceae) from China, Biodiversity Data Journal 9, pp. 63864-63864 : 63864

Paraeutypella citricola L.S. Dissan., Wijayaw., J.C. Kang & K.D. Hyde comb. nov.

Paraeutypella citricola Speg., in Anales del Museo Nacional de Buenos Aires 6: 245, (1898)

= Eutypella citricola Syd. & P. Syd., Hedwigia 49: 80 (1909), nom. illegit., Art. 53.1

Materials

Type status: Holotype. Record Level: institutionID: LPS-2120 Type status: Paratype. Occurrence: recordedBy: Nalin N. Wijayawardene; Taxon: kingdom: Fungi; phylum: Ascomycota; class: Sordariomycetes; order: Xylariales; family: Diatrypaceae; genus: Paraeutypella; specificEpithet: citricola; Location: country: China; county: Guiyang; locationAccordingTo: Guizhou University Garden (South); Identification: identifiedBy: L.S.Dissanayake; Event: year: 2019; month: October; day: 5; habitat: on a dead branch of Acer sp.; Record Level: type: paratype; institutionID: HMAS 290660, HMAS 290659; collectionID: culture KUMCC 20-0024, KUMCC 20-0023; institutionCode: Chinese Academy of Science, Kunming and Chinese Academy of Science Herbarium ; collectionCode: Kunming Institute of Botany Culture Collection

Description

Saprobic on dead twigs of Acer palmatum (Fig. 4 ). Sexual morph: Stromata immersed in bark of dead branches, erumpent, solitary or aggregated, circular to irregular in shape, superficial, carbonaceous. Ascomata 410-430 × 430-470 μm (x̅ = 420 × 450 µm, n = 10), perithecial, with groups of 4-6 perithecia arranged in a valsoid configuration, black, subglobose, clustered, immersed in ascostroma with ostiolar neck. Necks 360-390 μm long (x̅ = 375 µm, n= 10), papillate, sulcate, central ostiolar canal filled with paraphyses. Peridium 27-40 μm wide, composed of two layers of textura angularis; inner layer cells hyaline, outer layer cells dark brown to black. Hamathecium composed of 3-7 μm wide (x̅ = 5 µm, n= 10), hyaline, paraphyses arising from base of perithecia, composed of long, narrow, unbranched, septate, guttulate, narrowing and apically truncate. Asci 70-75 × 5-8 μm (x̅ = 72.5 × 6.5 μm, n = 20), 8-spored, unitunicate, thin-walled, clavate to cylindrical clavate, long pedicellate (40-50 μm), J- apical ring. Ascospores 7-10 × 2-3 μm (x̅ = 8.5 × 2.5 μm, n = 30), overlapping biseriate, allantoid, hyaline to light brown, smooth, aseptate, usually with guttules. Asexual morph: Undetermined.

Culture characteristics - Colonies on PDA, reaching 21 mm diam. after 2 weeks at 20-25oC, medium dense, circular to slightly irregular, slightly raised, cottony surface; colony from above: at first white, becoming buff; from below: yellowish-white at margin, yellow to brown at centre; mycelium yellowish.

Notes

Eutypella citricola was described by Spegazzini (1898) from Citrus in Argentina and has since been reported to cause dieback on various woody plants in warm temperate and tropical regions ( Farr and Rossman 2020). Eutypella citricola strains have previously been isolated from hosts such as Citrus limon , C. sinensis , C. paradisi , Salix spp., Schinus molle , Ulmus procera and Vitis vinifera ( Trouillas et al. 2011, Mehrabi et al. 2016). In our study, we provide additional information for P. citricola from dead stems of Acer ( Sapindaceae ) in China. In morphology, our collection (HMAS 290660) resembles Eutypella , thus having pustulate stromata with stout, converging ostiolar necks and asci with eight spores. According to phylogenetic analysis, KUMCC 20-0024 closely groups with a collection of E. citricola (IRAN 2349C), which was collected on dead branches of Salix sp. ( Salicaceae ) in Gilan Province, Iran ( Mehrabi et al. 2016) (Fig. 1). However, the IRAN 2349C strain is slightly different from our strain in having stromata with groups of 6-25 perithecia in a valsoid configuration and short ostiolar necks (100-300 µm), while our collection comprises stromata with groups of 4-6 perithecia in a valsoid configuration with a longer neck (356-385 μm). Based on phylogenetic analysis, both strains grouped in Paraeutypella sensu stricto (Fig. 1). Hence, the name Eutypella citricola is placed in Paraeutypella as P. citricola .

Paraeutypella guizhouensis , the type of Paraeutypella , morphologically resembles P. citricola both having immersed stromata, perithecia each with a long ostiolar neck and allantoid, aseptate ascospores with an oil droplet at each end. However, Paraeutypella citricola differs from P. guizhouensis by the number of perithecia within a stroma (4-6 vs. 6-12). A comparison of the ITS 1.0% (6/576) and β-tubulin 1.2% (5/406) between KUMCC 20-0024 and IRAN 2340C, ITS 1.0% (6/576) and β-tubulin 1.0% (5/406) between KUMCC 20-0024 and HVGRF01, HVVIT07 has been made.

Figures

Figure 4. Paraeutypella citricola (HMAS 290660) a-c. stromata on substrate; d. cross section of stroma; e. vertical section through stroma showing ostiolar necks and perithecia; f. ostiolar canal; g. peridium; h. paraphyses; i-k. asci; l-n. ascospores; o. germinating ascospore; p, q. culture on PDA after 6 weeks from above and below. Scale bars: 500 µm (b-d), 200 µm (e-g), 20 µm (g - l), 5 µm (m-o).