Two Novel Lasiodiplodia Species from Blighted Stems of Acer truncatum and Cotinus coggygria in China

SIMPLE SUMMARY: Lasiodiplodia species are plurivorous plant pathogens found worldwide, especially in tropical and subtropical regions, that result in fruit and root rot, die-back of branches and stem canker, etc. During the exploration of the fungal diversity of blighted stem samples collected in northern China, two new Lasiodiplodia species, L. acerina G.H. Qiao & W.T. Qin and L. cotini G.H. Qiao & W.T. Qin, were discovered based on integrated studies of phenotypic features, culture characteristics and molecular analyses. They were described and illustrated in detail. This work provided a better understanding of the biodiversity, phylogeny and established concepts of the genus Lasiodiplodia. ABSTRACT: The Lasiodiplodia are major pathogens or endophytes living on a wide range of plant hosts in tropical and subtropical regions, which can cause stem canker, shoot blight, and rotting of fruits and roots. During an exploration of the stem diseases on Acer truncatum and Cotinus coggygria in northern China, two novel species of Lasiodiplodia, L. acerina G.H. Qiao & W.T. Qin and L. cotini G.H. Qiao & W.T. Qin, were discovered based on integrated studies of the morphological characteristics and phylogenetic analyses of the internal transcribed spacer region (ITS), translation elongation factor 1-α (TEF1-α), beta-tubulin (TUB2) and RNA polymerase II subunit b genes (RPB2). Lasiodiplodia acerina is a sister taxon of L. henannica and distinguishable by smaller paraphysis and larger conidiomata. Lasiodiplodia cotini is closely related to L. citricola but differs in the sequence data and the size of paraphyses. Distinctions between the two novel species and their close relatives were compared and discussed in details. This study updates the knowledge of species diversity of the genus Lasiodiplodia. Furthermore, this is the first report of Lasiodiplodia associated with blighted stems of A. truncatum and C. coggygria in China.