Diatrype lancangensis S.H. Long & Q. R. Li, 2021

Long, Sihan, Liu, Lili, Pi, Yinhui, Wu, Youpeng, Lin, Yan, Zhang, Xu, Long, Qingde, Kang, Yingqian, Kang, Jichuan, Wijayawardene, Nalin N., Wang, Feng, Shen, Xiangchun & Li, Qirui, 2021, New contributions to Diatrypaceae from karst areas in China, MycoKeys 83, pp. 1-37 : 1

Diatrype lancangensis S.H. Long & Q. R. Li sp. nov.

Fig. 2

Holotype.

GMB0045.

Etymology.

Refers to the name of the location, where the type specimen was collected.

Description.

Saprobic on decaying branches of an unidentified plant. Sexual morph: Stromata immersed in bark, aggregated, irregular in shape, widely effused, flat, margin diffuse, surface dark brown to black, with punctiform ostioles scattered at surface, with tissues soft, white between perithecia. Entostroma dark with embedded perithecia in one layer. Perithecium semi-immersed in stroma, globose to subglobose, glabrous, with cylindrical neck, brevicollous or longicollous 283.5-343.5 μm high, 207-290 μm broad (av. = 315.5 × 248.0 μm, n = 10), ovoid, obovoid to oblong, monostichous, aterrimus. Ostiole opening separately, papillate or apapillate, central. Peridium 30-50 μm thick, dark brown to hyaline with textura angularis cell layers. Asci 90.5-160.5 × 7.0-15.0 μm (av. = 129.5 × 10.5 μm n = 30) 8-spored clavate, unitunicate, with rounded apex, apical rings inamyloid. Ascospores 11-18.5 × 2-4 μm (av. = 14.9 × 2.8 μm, n = 30), irregularly arranged, allantoid, slightly curved, brown to dark brown, smooth, aseptate, usually with oil droplets. Asexual morph: undetermined.

Culture characteristics.

Ascospores germinating on PDA within 24 hours. Colonies on PDA, white when young, became luteous, dense but, thinning towards edge, margin rough, white from above, reverse white at margin, pale yellow to luteous at centre, no pigmentation produced on PDA medium, no conidia observed on PDA or on OA media.

Specimens examined.

China, Yunnan Province, Baoshan City, Lancang River Nature Reserve (25°1'17.44"N, 99°35'10.05"E) on branches of an unidentified plant, 4 October 2019. Altitude: 2549 m., Y.H. Pi & Qiong Zhang, LC 172 (GMB0045, holotype, KUN-HKAS 112664, isotype, ex-type living culture GMBC0045) .

Additional specimens examined.

China , Yunnan Province, Baoshan City , Lancang River Nature Reserve (25°1'17.44"N, 99°35'10.05"E) on branches of an unidentified plant, 4 October 2019. Altitude: 2549 m., Y.H. Pi and Qiong Zhang, LC 173 (GMB0046, KUN-HKAS 112665, living culture GMBC0046); CHINA, Yunnan Province, Baoshan City, Lancang River Nature Reserve (25°1'15.48"N, 99°35'24.08"E) on branches of an unidentified plant, 5 October 2019. Altitude: 2623 m., Y.H. Pi and Qiong Zhang, LC 262 (GMB0047, KUN-HKAS 112672, living culture GMBC0047) .

Additional sequences.

GMB0045 (LSU: MW797057, RPB2: MW81490); GMB00046 (LSU: MW797058); GMB0047 (LSU: MW797060, RPB2: MW814903)

Note.

Our new strain, GMBC0045 falls into the unresolved clade (Clade 7) which comprises five Diatrypella and one Diatrype species (Fig. 1 ), this clade is consistent with the study of Konta et al. (2020). The taxonomic confusion of Diatrypaceae has led to difficulties in separating the genera. We consider that the new species belongs to the genus Diatrype , based on the stromata features mentioned above which closely resemble descriptions of Diatrype subundulata Lar. N. Vassiljeva & Hai X. Ma and Diatrype undulata (Pers.) Fr. (Vasilyeva et al. 2014). However, the ascospores of these species are larger than the ascospores of D. subundulata and D. undulata (Table 2 ). Phylogenetic analyses also showed that D. lancangensis falls on a separate branch that clustered with species of Diatrypella and Diatrype (Fig. 1 ). Hence, by combining morphological characteristics and phylogenetic analyses, it seems appropriate to categorise this species as Diatrype .

In the phylogenetic analyses, it can be seen that Clade 7 can be defined as a new genus, but it is difficult to find the common morphological similarities among these species. More specimens and sequence or chemical composition analysis are needed in the future to determine whether Clade 7 can be a new genus. The characteristics of the stromata of Diatrypella spp. in clade 7 are solitary and scattered, which is distinctly different from widely effuse, flat and slightly convex stromata of Diatrype lancangensis and Diatrype palmicola ( Liu et al. 2015; Hyde et al. 2020b; Zhu et al. 2021). And in the recent study, Zhu et al. (2021) proposed that the species of Diatrypella in Clade 7 were isolated from Betula spp., it may have host specificity. Because of the above two reasons, we think it is better to classify our strains into Diatrype .

Figures

Figure 1. Phylogram generated from Maximum Likelihood (RAxML) analyses, based on ITS-β-tubulin matrix. ML bootstrap supports (≥ 70 %) and Bayesian posterior probability (≥ 0.90) are indicated as ML / BYPP. The tree is rooted to Kretzschmaria deusta (CBS 826.72) and Xylaria hypoxylon (CBS 122620). Ex-type strains are in red. Newly generated strains are in black bold.

Figure 2. Diatrype lancangensis (GMB 0045, holotype) A stromata on host substrate B, C stromata on host D transverse sections through ascostroma E vertical section through ascostroma F culture on PDA G ostiolar canal H peridium I-K ascospores L-N asci. Scale bars: 10 μm (G-N).