Three novel species of fungi associated with pine species showing needle blight-like disease symptoms

Abstract

band and brown spot needle blights. Needles showing spots and/or bands with fruiting bodies were sampled. From 25 pine trees samples, 82 fungal isolates were successfully retrieved. The most common fungal genera were Pestalotiopsis (42.68%, n = 35), Rhizosphaera (28.04%, n = 23) and Cladosporium (9.75%, n = 8). Seven isolates could not be assigned to a species through molecular identification by ITS sequence analysis, potentially representing novel taxa. Based on multilocus phylogenetic analyses, using ITS, tub2 and tef1-α sequences, and morphological data, we propose three novel fungal species: Didymocyrtis pini sp. nov., Pestalotiopsis iberica sp. nov. and Rhizosphaera pinicola sp. nov. These species are potential active players in the symptomatology initially associated to red band and brown spot needle blight diseases. Although the pathogenicity of these fungi needs to be confirmed, this study suggests a high complexity underlying fungal species associated with these diseases which may impact disease epidemiology and management.

Towards resolvingNothophaeocryptopusandRhizosphaerainhabitants of spruce needles

“…S3), together with a species of Diaporthe (EDNA18-0051441_MDDF_6-2_3T_ITS, GenBank OP783986). It forms a well-supported clade sister to the recently described R. pinicola (Monteiro et al, 2022) and three sequences from isolates of an unnamed Rhizosphaera species from Korea on Pinus densiflora (Figure 2). This latter species was never formally named or published, but in a conference abstract (where the species was referred to as Rhizosphaera densiflorae), the authors observed that phylogenies from Tub2 provided better resolution, and were more strongly supported by bootstrap analysis, than for ITS (Park et al, 2006) which is consistent with our findings for this genus.…”

Pestalotiopsis jiangsuensis sp. nov. Causing Needle Blight on Pinus massoniana in China

“…In Pinus spp., it may be characterized by shoot blight, trunk necrosis, needle blight, and pinecone decay [ 54 ]. It is not uncommon that a species of Pestalotiopsis was successfully isolated from needles of Pinus species [ 34 ]. For example, Pestalotiopsis neglecta and P. citrina isolated from Pi.…”

“…For example, Pestalotiopsis neglecta and P. citrina isolated from Pi. sylvestris can cause the needles to turn yellow partially or completely and even cause death of the trees [ 29 , 34 ]. Pestalotiopsis bessey isolated from Pi.…”

“…The disease began to occur in 1974 and became popular in 1980, and it has become the main coniferous disease of trees [ 30 , 31 ]. Needle blight not only reduced the stock of trees but even led to the death of trees, which greatly threatened forestry production [ 32 , 33 , 34 ].…”

Endophytic Pestalotiopsis species associated with Rhododendron in Cangshan Mountain, Yunnan Province, China

“… Maharachchikumbura et al (2014) selected internal transcribed spacer (ITS), partial β-tubulin (TUB), and partial translation elongation factor 1-alpha (TEF1-α), along with morphological characters to resolve the identification of Pestalotiopsis . Up to now, in a total of 92 Pestalotiopsis species have been introduced based on morphological and phylogenetic evidence ( Maharachchikumbura et al, 2014 ; Liu et al, 2019 ; Rashmi et al, 2019 ; Shu et al, 2020 ; Monteiro et al, 2022 ). Pestalotiopsis is ordinarily isolable as endophytes in plants ( Aly et al, 2010 ; Watanabe et al, 2010 ; Maharachchikumbura et al, 2012 ).…”