Morphological and phylogenetic analyses reveal a new genus and two new species of Tubakiaceae from China

Abstract

Species of Tubakiaceae have often been reported as plant pathogens or endophytes, commonly isolated from a wide range of plant hosts. The isolated fungi were studied through a complete examination, based on multilocus phylogenies from combined datasets of ITS/LSU/rpb2 and ITS/tef1/tub2, in conjunction with morphological characteristics. Five strains isolated from Lithocarpus fohaiensis and Quercus palustris in China represented a new genus of Tubakiaceae, Obovoideisporodochium and three species, viz. Obovoideisporodochium lithocarpi sp. nov., Tubakia lushanensis sp. nov. and T. dryinoides.

Phaeotubakia lithocarpicola gen. et sp. nov. (Tubakiaceae, Diaporthales) from leaf spots in China

“…The sequences obtained in the current study were assembled using SeqMan v. 7.1.0, and reference sequences were retrieved from the website of the National Center for Biotechnology Information ( NCBI , https://www.ncbi.nlm.nih.gov ; accessed on 15 October 2022), based on sequences from Braun et al (2018) and Zhang et al (2021) . The sequences were aligned using MAFFT v. 7 and corrected manually using MEGA v. 7.0.21 ( Katoh et al 2019 ).…”

“…Phaeotubakia lithocarpicola represents the third tubakiaceous species discovered from the host genus Lithocarpus. However, P. lithocarpicola differs from O. lithocarpi and T. californica by brown conidiogenous cells and brown to dark brown conidia (Braun et al 2018;Zhang et al 2021).…”

“… Tubakiaceae was proposed as a diaporthalean family based on its type genus Tubakia , and the other seven genera, namely Apiognomonioides , Involutiscutellula , Oblongisporothyrium , Paratubakia , Racheliella , Saprothyrium and Sphaerosporithyrium ( Braun et al 2018 ). Subsequently, Ellipsoidisporodochium and Obovoideisporodochium were added to this family based on morphological and phylogenetical evidence ( Zhang et al 2021 ; Liu et al 2022 ). Hence, ten genera have been accepted in Tubakiaceae before the present study.…”

“…However, some species also form crustose or pustulate pycnidioid conidiomata, for example, Tubakia californica is known to only have crustose pycnidioid conidiomata during its lifecycle ( Braun et al 2018 ). Moreover, conidia of tubakiaceous species are globose, subglobose, ellipsoid, broad ellipsoid-obovoid to subcylindrical or somewhat irregular in shape, aseptate, hyaline, subhyaline to pigmented ( Braun et al 2018 ; Zhang et al 2021 ). Conidia of Apiognomonioides , Ellipsoidisporodochium , Oblongisporothyrium , Obovoideisporodochium and Saprothyrium species are known to be hyaline ( Braun et al 2018 ; Zhang et al 2021 ; Liu et al 2022 ).…”

“…Moreover, conidia of tubakiaceous species are globose, subglobose, ellipsoid, broad ellipsoid-obovoid to subcylindrical or somewhat irregular in shape, aseptate, hyaline, subhyaline to pigmented ( Braun et al 2018 ; Zhang et al 2021 ). Conidia of Apiognomonioides , Ellipsoidisporodochium , Oblongisporothyrium , Obovoideisporodochium and Saprothyrium species are known to be hyaline ( Braun et al 2018 ; Zhang et al 2021 ; Liu et al 2022 ). Conidia of Involutiscutellula , Paratubakia and Sphaerosporithyrium species are hyaline to slightly pigmented ( Braun et al 2018 ), while conidia of Racheliella and Tubakia species are hyaline to pigmented ( Braun et al 2014 , 2018 ; Zhu et al 2022 ).…”