Phytotaxa 514 (2): 105–117 https://www.mapress.com/j/pt/ Copyright © 2021 Magnolia Press Article PHYTOTAXA ISSN 1179-3155 (print edition) ISSN 1179-3163 (online edition) Accepted by Sinang Hongsanan: 17 Dec. 2020; published: 13 Aug. 2021 https://doi.org/10.11646/phytotaxa.514.2.2 105 Diplodia parva sp. nov., a novel species of the family Botryosphaeriaceae isolated from soil in Korea SEUNG-YEOL LEE a,b,e , LEONID N. TEN a,f , BENJAMIN YAW AYIM c,g , OKOUMA NGUIA FULBERT d,h , KALLOL DAS a,i & HEE-YOUNG JUNG a,b,j * a School of Applied Biosciences, Kyungpook National University, Daegu 41566, Republic of Korea. b Institute of Plant Medicine, Kyungpook National University, Daegu 41566, Republic of Korea. c Ministry of Food and Agriculture, Plant Protection and Regulatory Services Directorate, -Ashanti 23321, Ghana d Gabon Ministry of Agriculture, Food and Fishery, Agriculture Direction General, BP 271 Libreville, Gabon e leesy1123@knu.ac.kr; https://orcid.org/0000-0003-1676-0330 f lten3@yahoo.com; https://orcid.org/0000-0003-1566-198X g b.ayim@yahoo.com; https://orcid.org/0000-0001-6319-746X h fulbert.okoumanguia@yahoo.fr; https://orcid.org/0000-0003-0017-779X i kalloldas91@gmail.com; https://orcid.org/0000-0003-0906-3983 j heeyoung@knu.ac.kr; https://orcid.org/0000-0002-4254-3367 *Corresponding author: heeyoung@knu.ac.kr Abstract A fungal strain designated KNU16-007, belonging to the family Botryosphaeriaceae, was isolated from soil in Daegu, Korea. Phylogenetic analyses based on the concatenated nucleotide sequences of the ITS and TEF-1α regions, showed that the isolate resides in a clade together with Diplodia species but occupies a distinct phylogenetic position. Conidial dimensions of strain KNU16-007 (22.7–29.3 μm × 8.9–10.9 μm) or its conidial length:width ratio were significantly differed from those of the closely related D. sapinea, D. intermedia, D. scrobiculata, D. seriata, D. crataegicola, D. rosacearum, and D. citricarpa clearly indicating morphological differences from these species. Detailed descriptions, illustrations, and discussions regarding the morphological and phylogenetic analyses of the closely related species are provided to support the novelty of the isolated species. The results of phylogenetic analysis and morphological observations indicate that strain KNU16-007 represents a novel species in the genus Diplodia, for which the name Diplodia parva sp. nov. is proposed. Keywords: Botryosphaeriaceae, Diplodia, phylogeny, taxonomy Introduction The species belonging to Botryosphaeriaceae are cosmopolitan, distributed almost worldwide, and members of this family are necrotrophic, pathogenic, or saprobic, especially in woody plants (Slippers et al. 2007, Phillips et al. 2013, Doilom et al. 2015, Coutinho et al. 2018). The genus Diplodia of the family Botryosphaeriaceae has a worldwide distribution, and similar to other members of Botryosphaeriaceae, species are known to be pathogens, endophytes, and latent pathogens of a variety of plants (Crous et al. 2006, Slippers et al. 2007). Among the members of Botryosphaeriaceae, species of Diplodia can be distinguished by conidial characteristics such as being relatively thick-walled, hyaline or brown, aseptate or 1-septate, and mostly ovoid with round ends (Phillips et al. 2013). Typically, the conidia remain hyaline for a long time before they become brown and septate, but in Diplodia seriata De Not., Diplodia pinea (Desm.) J. Kickx f., and Diplodia scrobiculata J. de Wet, Slippers & M.J. Wingf. the conidia become brown before discharge from the pycnidia, however, it is difficult to identify the species using only morphological characteristics (Phillips et al. 2012, Phillips et al. 2013). The application of DNA sequence analysis and molecular phylogenetic analyses had a major impact on the systematics of the Botryosphaeriaceae. The first phylogenic analysis based on the sequences of the internal transcribed spacer (ITS) region of 22 strains, including Diplodia quercina Westend. and Diplodia mutila (Fr.) Mont., was performed for the Botryosphaeriales more than 20 years ago (Jacobs et al. 1998). The sequence of ITS regions is still the most widely used for Diplodia phylogeny but usually in combination with other loci such as the translation elongation factor 1-alpha (TEF1-α) (Damm et al. 2007). Comprehensive descriptions of eighteen Diplodia species by Phillips et al. (2013) were supplemented by phylogenetic trees based on the combined analysis of the ITS