Tubifera khangaiensis A. Vlasenko, 2024

Vlasenko, Anastasia V., Enkhtuya, Ochirbat, Degidmaa, Turmunkh, Enkhjargal, Enkhtaivan, Chelobanov, Boris P. & Vlasenko, Vyacheslav A., 2024, Three new species of bright-spored myxomycetes from Asia and the second world record of Perichaena maculosa, Phytotaxa 663 (4), pp. 205-220 : 215-218

Tubifera khangaiensis A. Vlasenko sp. nov. ( Figs. 8 , 9 ).

MycoBank no: 855058

Etymology:— Named after the Khangai Mountains in Mongolia.

Pseudoaethalia sessile, umber, with a bluish tint, 10–14 mm diam., up to 6 mm tall, dehiscence irregularly. Individual sporangia in the form of irregular cylinders, curved, merging only in the lower part, middle and upper parts remain free, often expanding towards the upper part. Individual sporangia 5 mm tall, 0.8–1.1 diam. Hypothallus inconspicuous. Capillitium well developed, threads sinuous, branching, colorless in transmitted light, spores attached to the threads, individual threads up to 5–6 μm in diam., many sporangia free, irregularly rounded nodules are formed, smooth, reddish-brown in transmitted light, 10–40 μm diam. Spores in mass light umber, light brown, with reddish tint in transmitted light, spherical, 6–7 µm diam., ornamented with a mesh of 8–9 cells on the visible part of the spore. Plasmodium unknown.

Holotype:— MONGOLIA. Bayankhongor: Khangai Mountains, near Khukh Lake , larch forest, on fallen trunk of Larix sp. , 47°31’21” N, 98°31’04” E, 2192 m a.s.l., field sample coll. 8 August 2023, A. V. Vlasenko, ident. A. V. Vlasenko, NSK 1013200 , GenBank No.: PQ032479.

Other specimen examined:— MONGOLIA. Arkhangai: Khangai Mountains, 11 km southwest of Khunt village, larch forest, on fallen trunk of Larix sp. , 47°46’32” N, 99°16’45” E, 2201 m a.s.l., field sample coll. 8 August 2023, A. V. Vlasenko, ident. A. V. Vlasenko, NSK 1013201, GenBank No.: PQ032480. Eсology:— Grows as a xylobiont on fallen trunk of Larix .

Comments:— The colour of the pseudoaethalia of Tubifera khangaiensis resembles T. dimorphotheca Nann. - Bremek. & Loer., T. microsperma (Berk. & M.A. Curtis) G.W. Martin , T. papillata G.W. Martin, K.S. Thind & Sohi. However , the pseudoaethalia of these species have a clearly visible stalk-like structure from the hypothallus (false stalk), whereas the pseudoaethalia of T. khangaiensis are sessile, the hypothallus is inconspicuous, and the false stalk is absent. Sporangia of T. khangaiensis are connected to neighboring sporangia only in the lower part, in the middle and upper parts they remain free, often individual sporangia expand in the upper part, which distinguishes the new species from all previously described species in the genus Tubifera . The presence of free, irregularly shaped nodules inside the sporangia in T. khangaiensis is similar to T. dictyoderma Nann. -Bremek. & Loer and T. papillata G.W. Martin, K.S. Thind & Sohi. However , the spores of T. dictyoderma and T. papillata are smaller and ornamented with a coarse mesh with 3–4 cells per visible part of the spore, whereas the spores of T. khangaiensis are ornamented with a mesh of 8–9 cells per visible part of the spore.

The ML analysis based on the 18S nrDNA region ( Fig. 10 ) showed that Tubifera khangaiensis is an independent species, closest to T. applanata Leontyev & Fefelov. The genetic distance of the T. khangaiensis branch on the SSU tree is 0.138, with 100% bootstrap support.

Figures

FIGURE 8. Tubifera khangaiensis (Holotype). A–B. Pseudoaethalia (RL). C. Part of pseudoaethalia (RL). D. Peridium and capillitium (RL). E–F. Spores on threads of capillitium (TL). G. Capillitium, free rounded node of capillitium and spores (TL). Scale bars:A–B = 2.5 mm, C = 2 mm, D = 1 mm, E = 100 µm, F = 15 µm, G = 25 µm.

FIGURE 9. Tubifera khangaiensis (holotype). A. Spores on threads of capillitium (SEM). B–C. Capillitium and spores (SEM). D. Ornamentation of inner surface of the peridium (SEM). E–F. Spores (SEM). Scale bars: A = 100 µm, B = 10 µm, C = 20 µm, D = 10 µm, E–F = 1 µm.

FIGURE 10. Maximum likelihood tree based on 18S nrDNA sequences shows the phylogenetic relationships between Tubifera khangaiensis and closely related species of the genus Tubifera. BS values with high support and Bayesian posterior probabilities are shown in the branches. GenBank accession numbers are given after the species name.