Laburnicola zaaminensis Htet, Gafforov, Mapook & K.D. Hyde, 2021

Htet, Zin Hnin, Mapook, Ausana, Gafforov, Yusufjon, Chethana, K. W. Thilini, Lumyong, Saisamorn & Hyde, Kevin D., 2021, Molecular phylogeny and diversity of Laburnicola (Didymosphaeriaceae): a new species from Uzbekistan, Phytotaxa 527 (3), pp. 177-190 : 182-184

Laburnicola zaaminensis Htet, Gafforov, Mapook & K.D. Hyde , sp. nov. ( Fig. 2 )

Mycobank No: MB840713

Facesoffungi number: FOF 09516

Etymology:— Named after the location that the specimens collected, Zaamin National Park, Uzbekistan.

Holotype:— TASM 6152

Description:— Saprobic on dead stems of Rosa sp. Sexual morph: Undetermined. Asexual morph: Coelomycetous, Conidiomata 120–230 × 135–140 µm (x = 124 ×138 µm, n=5), superficial, solitary, globose, unilocular, no ostiole, appear as black tiny spots on host. Peridium 16–20 µm wide, comprised of several layered of blackish to dark brown cells of textura angularis, cells towards inside lighter and darker at the outer part. Conidiophores reduced to conidiogenous cells. Conidiogenous cells 3–4 × 4–5 µm (x = 3.5 ×4 µm, n=5), holoblastic, ellipsoidal to ovoid, swollen at the base, hyaline, discrete, producing a single conidium at the apex. Conidia 3–5 × 1–3 µm (x = 4 × 2 µm, n=20), oblong to cylindrical, hyaline, aseptate.

Material examined:— Uzbekistan, Jizzakh Province , Zaamin District , Turkestan range of Pamir – Alay Mountains , Zaamin National Park, Ettisuv River, on dead stems of Rosa sp. , 10 July 2019, Y. Gafforov YG-Z30-1 (holotype, TASM 6152 ) .

Notes:— Our phylogenetic analysis showed that L. zaaminensis strain TASM 6152 is closely related to L. dactylidis with high bootstrap support (ML=90%, BI=1.00) ( Fig. 1 ). However, Laburnicola zaaminensis is an asexual taxon, while L. dactylidis was documented as a sexual morph in Wanasinghe et al. (2016). There are no reports on the asexual morph of L. dactylidis yet. Hence, we could not compare the morphology of our new taxon with L. dactylidis .

According to the BLASTn results, the closest match for the LSU sequence of L. zaaminensis was L. muriformis ( MFLUCC 14-0921) with 98.96% similarity. The closest match for SSU sequence was Paraconiothyrium rosae ( MFLU 15-1115) with 98.49%. The closest match for ITS sequence was Laburnicola sp. (TU32) with 94.95% similarity, and the closest match for TEF 1-ɑ with 93.26% similarity was L. rhizohalophila (strain R22-15). Furthermore, comparisons of the ITS gene region between L. zaaminensis and L. dactylidis shows nine basepair differences (1.9%) across 464 nucleotides and the LSU gene region shows three basepair differences (0.35%) across 854 nucleotides.

Laburnicola zaaminensis is distinct from L. rhizohalophila in having small, oblong to cylindrical, hyaline, aseptate conidia (3–5 × 1–3 µm), while L. rhizohalophila has 0-1 transverse septa, hyaline to dark pigmented, peanutlike thalloconidia (20.4–35.4 × 5.2–10.1 µm). Based on the evidence of our phylogenetic analysis and contrasting morphology with the related taxon, Laburnicola zaaminensis is introduced herein as a new species. Laburnicola rhizohalophila ( Yuan et al. 2020) is the first asexual morph in the genus, and this is the first coelomycete reported in the genus.

Figures

FIGURE 1. Phylogram generated from maximum likelihood analysis based on combined LSU, SSU, ITS and TEF 1-ɑ sequence data. Periconia citlatepetlensis strains (IOM 325319, IOM 325319.2) are used as the outgroup. Bootstrap support values for ML equal to or greater than 60% and BYPP equal to or greater than 0.95 are given above the branches. The ex-type strains are in bold and black; the new isolate is in bold and red.

FIGURE 2. Laburnicola zaaminensis (holotype, TASM 6152). a,b Appearance of conidiomata on host substrate. c Section through conidiomata. d Peridium. e Conidia on the conidiogenous cells. f–g Conidia. Scale bars: a, b = 500 µm. c = 50 µm. d = 10 µm. e, f, g= 5 µm.