Kallichroma ellipsoideum Abdel-Wahab, Bahkali & E.B.G. Jones, 2016

Abdel-Wahab, Mohamed A., Bahkali, Ali H., Gareth Jones, E. B., Elgorban, Abdallah M., Abdel-Aziz, Faten A., Hodhod, Mohamed S. & Al-Hebshi, Mohamed O., 2016, Two new species of Kallichroma (Bionectriaceae, Hypocreales) from Saudi Arabian mangroves, Phytotaxa 260 (1), pp. 66-74 : 70-71

Kallichroma ellipsoideum Abdel-Wahab, Bahkali & E.B.G. Jones sp. nov. Figure 3

Index Fungorum number: IF551854; Facesoffungi number: FoF 01806; MB 816855.

Etymology: —In reference to the shape of the ascospores.

Holotype: CBS H-22562.

Saprobic on decayed, whitish, decorticated intertidal mangrove wood. Sexual morph: Ascomata 110–220 μm diam., perithecoid or stromatic, when stromatic consists of groups of two to three confluent ascomata, immersed with papillae protruding above the wood surface, hyaline with yellow to apricot colored exudates in the surrounding host’s wood, carotenoids are concentrated in lipid globules that are mainly located in the centrum surrounding asci. Papillae 125–175 μm long, 135–165 μm wide, as large as the ascomatal venter, hyaline. Ostiolar canal 120–135 μm long, 42–55 μm wide, conical in shape and periphysate. Periphyses 23–40 μm long, 1–1.5 μm thick. Peridium 15–33 μm thick around the ascomatal venter, with one layer of flattened, narrow, thick-walled cells, forming textura angularis, 9–11 cell layers. Peridium 35–60 μm thick around the papillae, hyaline, one-layered forming textura intricata or textura angularis. Hamathecium composed of apical paraphyses, simple filaments, unbranched and non-septate, 1–2 μm thick, evanescent. Asci 40–85 (x = 67.8, S.D. = 16.22, n = 17) μm long, 9–15 (x = 12.8, S.D. = 3.09, n = 17) μm wide, 3 to 8-spored, clavate, short pedicellate, unitunicate, thin-walled, persistent, developing at the lower part of the ascomatal venter. Ascospores 13–21 (x = 17.2, S.D. = 2.86, n = 55) μm long, 5–8 (x = 6.9, S.D. = 1.26, n = 55) μm wide, hyaline, ellipsoidal, clavate, uni- or biseriate, unicellular or one-septate, slightly constricted at the septum, with median or submedian septum, smooth walled. Asexual morph: Unknown.

Culture characters:—Ascospores germinating on PDA within 24 h and germ tubes produced from both ascospore cells. Colonies 15 to 20 mm diam. in 20 days at 23ºC, circular, with irregular margin, produce white to dull-yellow aerial and immersed mycelia with yellow exudates.

Material examined: — SAUDI ARABIA, Red Sea, Yanbu City, Yanbu mangroves, on submerged decayed wood of the mangrove tree Avicennia marina , 17 November 2011, M. A. Abdel-Wahab ( CBS H-22562, holotype) ; SAUDI ARABIA, Red Sea, Jizan City, Farasan Island mangroves, on submerged decayed wood of the mangrove tree Avicennia marina , 8 March 2012, M. A.Abdel-Wahab (MF1209) ; SAUDI ARABIA, Arabian Gulf, Tarut mangroves, on submerged decayed wood of the mangrove tree Avicennia marina , 28 March 2013, M. A. Abdel-Wahab (MF1347) .

Notes:— Ascomata in Kallichroma glabrum and K. tethys are 275–380 μm high, 315–460 μm in diam., orangeyellowish in color, resulting from cartenoids concentrated in lipid globules that are mainly located in the upper tissues (peridium, paraphyses and periphyses) ( Kohlmeyer & Kohlmeyer 1965, 1979, Kohlmeyer & Volkmann-Kohlmeyer 1993). Both K. asperum and K. ellipsoideum have perithecoid or stromatic ascomata with large, globose papillae protruding above the wood surface (Figs. 2,3). Ascomata in K. asperum are orange to reddish-orange in color and larger (300–400 μm diam.) than ascomata in K. ellipsoideum (110–220 μm diam.) that are hyaline in color. Both species have 3 to 8-spored asci vs. 8-spored asci in K. glabrum and K. tethys . The orange color of ascomata in K. asprum results from carotene concentrated in the peridium while in K. ellipsoideum carotene are concentrated in lipid globules that are mainly located in the centrum surrounding asci. K. ellipsoideum differs from K. tethys , K. glabrum and K. asperum by having small, hyaline ascomata with large globose papillae; smaller asci and small hyaline, unicellular or one-septate, ellipsoidal ascospores with smooth walls. Moreover, the new taxon is phylogenetically distinct from as it forms a sister group to other Kallichroma species. ( Fig. 1 ).

Figures

FIGURE 1. Phylogenetic relationships of the two new Kallichroma species with other Kallichroma species based on the nucleotide sequences of the combined SSU and LSU rDNA. The maximum likelihood tree (ML) (-ln likelihood = 8219.02318) was constructed as described in the text. The 100% pp values are indicated by bold branches. The numbers indicate ML and MP bootstrap values ≥ 60%. The tree is rooted to representatives of Xylariales. The new Kallichroma species are in yellow.

FIGURE 3. Kallichroma ellipsoideum (CBS H-22562, holotype) A. Vertical section of ascoma. B–D. Asci at different stages of development. E. Ascospores. Scale bars: A = 20 μm, B–D = 10 μm, E = 5 μm. \