Heveicola xishuangbannaensis R.F. Xu, K.D. Hyde & Tibpromma, 2022

Xu, Ruifang, Hyde, Kevin D., Karunarathna, Samantha C., Xu, Jian-Chu, Mortimer, Peter E. & Tibpromma, Saowaluck, 2022, Morphology and multi-gene phylogeny reveal a new fungal genus and species from Hevea brasiliensis latex in Yunnan, China, Phytotaxa 530 (1), pp. 65-76 : 70-71

Heveicola xishuangbannaensis R.F. Xu, K.D. Hyde & Tibpromma , sp. nov. ( Fig. 2 )

Index Fungorum Number: IF558799 ; Facesoffungi Number: FOF10491

Holotype:— HKAS 115759

Etymology:— named after the location Xishuangbanna where the fungus was first discovered.

Saprobic on rubber latex of Hevea brasiliensis . Sexual morph: Undetermined. Asexual morph: Hyphomycetous. Colonies on natural substrate consisting of long, effuse, dark synnemata, scattered, somewhat hairy, mass of spores all over the surface. Synnemata 850–1000 × 90–135 μm (x̅=943 × 112 μm, n=6), consisting of pale brown to dark brown, cylindrical, septate, unbranched, smooth-walled conidiophores. Conidia 15–40 × 5–8 μm (x̅=26.6 × 6.5 μm, n=20), catenate, cylindrical, 0–4 to multiseptate (on PDA, conidia up to 20-septate), slightly constricted at median septum, rounded at both ends, formed in acropetal chains, initially hyaline, then pale brown to brown, often with a dark brown band at the septa, guttulate, thick- and rough-walled.

Culture characteristics:— cultures on PDA, colonies slow growing, umbonate, curled, smooth, edges brown, dark brown, mycelia 2.5–6 μm wide, hyaline, septate, conidia 10–70 × 5–12 μm (x̅=27.7 × 6.8 μm, n=30), oblong, up to 20-septate, pale brown to brown, thick- and rough-walled ( Fig. 3 ).

Material examined:— CHINA. Yunnan Province: Xishuangbanna Tropical Botanical Garden, on old rubber latex (oozing from the trunk) of Hevea brasiliensis Müll.Arg. , 24 November 2020, Ruifang Xu , XSBNR-07 ( HKAS 115759 , holotype); ex-type living cultures KUMCC 21-0086 .

Notes: — In the phylogenetic analyses Heveicola xishuangbannaensis forms a monophyletic branch within Wiesneriomycetaceae with strong statistical support ( Fig. 1 ). Heveicola xishuangbannaensis is similar to Speiropsis and Phalangispora in the shape and colour of the conidia, but it can differ in having a dark brown band at the septa and branches. No sexual morph has been reported so far in Wiesneriomycetaceae .

Figures

FIGURE 1. RAxML tree based on a combined dataset of LSU, SSU, rpb2 and tef1-α partial sequences. Bootstrap support values for maximum likelihood (ML) equal to or higher than 60% and Bayesian probability (BYPP) equal to or higher than 0.90 are given above/ below the branches. Newly generated sequences are shown in red.

FIGURE 2.Heveicolaxishuangbannaensis (HKAS115759,holotype).A–C.Appearanceof colonieson thesubstrate.D, E.Conidiophores with conidia. F–O. Conidia. Scale bars: D–F = 50 μm, G–I, K, L = 10 μm, J, M–O = 30 μm.

FIGURE 3. Heveicola xishuangbannaensis (KUMCC 21-0086, ex-type) on PDA.A. Germinated conidium. B, C. Upper and lower view of cultures on PDA. D–F, K. Synnemata on PDA medium. G–I. Conidia growing from mycelia. L. Conidiophores with conidia. J, M. Conidia. Scale bars:A, G = 50 μm, F = 500 μm, H = 100 μm, I = 40 μm, J, L, M = 30 μm, K = 150 μm.