Rhytidhysteron ligustrum X.L. Xu & C.L. Yang

Senwanna, Chanokned, Suwannarach, Nakarin, Phookamsak, Rungtiwa, Kumla, Jaturong & Hongsanan, Sinang, 2023, New host and geographical records of Rhytidhysteron in northern Thailand, and species synonymization, Phytotaxa 601 (2), pp. 157-173 : 168

Rhytidhysteron ligustrum X.L. Xu & C.L. Yang , in Xu et al., Cryptog. Mycol. 43(3): 67 (2022)

Synonym:— Rhytidhysteron mengziense T.Y. Du & Tibpromma , in Du et al., Journal of Fungi 9(2, no. 148): 13 (2023)

Description:— See Xu et al. (2022).

Notes:— Rhytidhysteron ligustrum and R. mengziense were recently reported from Ligustrum quihoui ( Oleaceae ) and Crataegus scabrifolia (Rosaceae) , respectively ( Xu et al. 2022, Du et al. 2023). Based on phylogenetic analyses of Xu et al. (2022) and Du et al. (2023), these two species are closely related to R. camporesii . However, they differ in nucleotide differences in the ITS and TEF1 regions as well as the size of ascomata, asci and ascospores, ascospore wall, number of septations of mature ascospores, and type of exciple wall in comparison to R. camporesii . In our multigene phylogenetic analyses, R. ligustrum is closely related to R. mengziense as they clustered together with 100% ML and 1.00 PP statistical support ( FIGURE 1 ). Sequence comparisons of LSU, ITS, SSU, and TEF1 genes between R. ligustrum and R. mengziense showed they are 100% similar. However, they are different in size of asci and ascospores ( Xu et al. 2022, Du et al. 2023). We could not find any significant morphological (except for asci and ascospore size) and phylogenetic differences between these two species. Therefore, we treat R. mengziense as a synonym of R. ligustrum , following the principle of priority for the earliest available name.

Figures

FIGURE 1. Phylogenetic tree conducted by maximum likelihood (RAxML) based on analysis of a combined LSU, ITS, SSU, and TEF1 sequence data of Rhytidhysteron species. Bootstrap values for ML equal to or greater than 60% and Bayesian posterior probabilities (PP) equal to or greater than 0.90 are defined as ML/PP above the nodes. The tree is rooted to Gloniopsis calami (MFLUCC 15-0739) and G. praelonga (CBS 112415). The newly generated strains are indicated in blue and the type strains are in black bold.