Pseudodiatrype 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

Pseudodiatrype S.H. Long & Q.R. Li gen. nov.

Etymology.

Refers to this genus resembling Diatrype in morphology, but it is phylogenetically distinct.

Type species.

Pseudodiatrype hainanensis S. H. Long & Q.R. Li sp. nov.

Description.

Saprobic on decaying branches of an unidentified plant. Sexual morph: Stromata scattered or aggregated on host, wart-like, pustulate, visible as black, rounded to irregular in shape on host surface, erumpent through host bark, 5-20 ascomata immersed in one stroma. Endostroma consists of outer layer of black, small, dense, thin parenchymal cells and inner layer of white, large, loose parenchymal cells, thin, pale yellow, powdery near margin of the black cells. Ostiole opening through host bark and appearing as black spots, separately, papillate or apapillate, central. Perithecium immersed in stroma, globose to subglobose, glabrous, with cylindrical neck, brevicollous or longicollous. Peridium is composed of an outer layer of dark brown to black, thin-walled cells, arranged in textura angularis, the inner layer of hyaline thin-walled cells of textura angularis. Asci 8-spored, unitunicate, clavate, long-stalked, apically rounded, apical rings inamyloid. Ascospores irregularly arranged, allantoid, slightly or moderately curved, smooth, subhyaline, aseptate, usually with two oil droplets. Asexual morph: undetermined.

Note.

The genus Pseudodiatrype is introduced to accommodate the new collection made from Hainan Province of China and typified by Pseudodiatrype hainanensis . Pseudodiatrype is monotypic and, morphologically, resembles Diatrype and Allodiatrype Konta & K.D. Hyde. However, Pseudodiatrype can be distinguished from Diatrype by its 5-20 ascomata immersed in a stroma, while the stroma of species of Diatrype is distributed over large areas, sometimes covering the surface of the host ( Vasilyeva and Ma 2014; Konta et al. 2020). Pseudodiatrype differs from Alloiatrype by having its 5-20 ascomata immersed in a stroma, whereas the stroma of Allodiatrype has only 1-10 ascomata. Moreover, the endostroma of Allodiatrype is composed of dark brown outer layer cells and yellow inner layer cells ( Konta et al. 2020), which are different from the endostroma of Pseudodiatrype having black outer and inner cells surrounded by powdery, pale yellow cells. In addition, the sizes of stroma and ascospores are different from species of Diatrype and Allodiatrype (Table 2 ). In the phylogenetic analyses, species of Pseudodiatrype appeared in a separate branch which is distinct from other genera within Diatrypaceae (Fig. 1 ), thus, justifying the erection of the new genus Pseudodiatrype .

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.