Biodiversity Data Journal : Taxonomic Paper
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Taxonomic Paper
Two new species of Neopestalotiopsis from southern China
expand article infoQi Yang, Xiang-Yu Zeng, Jun Yuan, Qian Zhang, Yu-Ke He§, Yong Wang
‡ Department of Plant Pathology, Agricultural College, Guizhou University, Guiyang, China
§ Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, Thailand
Open Access

Abstract

Background

Pestalotiopsis-like fungi are widely distributed in many plants and include endophytes, pathogens and saprobes. Five strains of Neopestalotiopsis were isolated from diseased leaves of Rhapis excelsa (Principes, Palmae), Rhododendron simsii and Rho. championiae (Ericales, Ericaceae) and Erythropalum scandens (Santalales, Olacaceae) in southern China.

New information

Based on morphology and multi-gene (ITS, tub2, tef1) phylogeny, our five strains of Neopestalotiopsis represent two new species and one extant species. Descriptions, illustrations and notes are also provided for the new species.

Keywords

two new taxa, Sporocadaceae, taxonomy

Introduction

Sporocadaceae was introduced by Corda (1842) and comprised abundant endophytic, plant pathogenic or saprobic taxa (Liu et al. 2019). A great part of Sporocadaceae species were reported as important plant pathogenic fungi that mainly harm various economic crops, such as tea, blueberry and elephant apple (Fernández et al. 2015, Banerjee et al. 2018, Tsai et al. 2020). Jaklitsch et al. (2016) synonymised Bartaliniaceae, Discosiaceae, Pestalotiopsidaceae and Robillardaceae under Sporocadaceae. Liu et al. (2019) studied the taxonomy of Sporocadaceae and accommodated 30 genera in it. Hyde et al. (2020) and Wijayawardene et al. (2020) placed Sporocadaceae in Amphisphaeriales and accepted 33 genera.

Neopestalotiopsis was introduced by Maharachchikumbura et al. (2014) to accommodate pestalotiopsis-like taxa that had versicolorous median cells and indistinct conidiophores. Until now, 49 taxa of Neopestalotiopsis are known (Mycobank 2021: https://www.mycobank.org/page/Home). This group commonly occurs on plants as endophytes, pathogens or saprobes (Jeewon et al. 2004, Liu et al. 2010, Hyde et al. 2016, Reddy et al. 2016, Shetty et al. 2016, Ran et al. 2017, Bezerra et al. 2018, Freitas et al. 2019). Recently, research showed them as plant pathogens causing stem blight, flower bight, twig dieback and fruit rot (Akinsanmi et al. 2016, Borrero et al. 2017, Mahapatra et al. 2018, Rodríguez-Gálvez et al. 2020). In the past few years, China and Thailand are places where most species of Neopestalotiopsis were found (Norphanphoun et al. 2019).

Amongst surveys of microfungi in southern China, we made five collections of Neopestalotiopsis from four host plants. Based on morphological descriptions and molecular analyses of three gene loci, our strains represent two new species and one known species.

Materials and methods

Sample collection and fungi isolation

Diseased leaf samples with fruiting bodies were collected from major botanical gardens in Yunnan, Guangxi and Guizhou Provinces in southern China. After surface disinfection of the diseased tissues (Zhang et al. 2020), the single-spore method was used for obtaining a pure culture (Senanayake et al. 2020). The isolates were transferred to new potato dextrose agar (PDA) plates to obtain a pure strain.

Morphology study

Cultures growing on potato dextrose agar (PDA) were incubated under moderate temperatures (28ºC) for 2−4 weeks in 12 h daylight. The diameter of cultures was measured after 1 week and the colour was determined with the colour charts of Rayner (1970). The morphological features were noted and recorded following Hu et al. (2007). Microscopic preparations were prepared in lactophenol and over 30 measurements were obtained per structure. Photographs were taken using a compound microscope (Olympus BX53, Japan). The holotype specimens were deposited in the Herbarium of Department of Plant Pathology, Agricultural College, Guizhou University (HGUP). Ex-type cultures were deposited in the Culture Collection at the Department of Plant Pathology, Agriculture College, Guizhou University, China (GUCC).

DNA extraction and PCR amplification

DNA extraction and PCR amplification follow Dissanayake et al. (2020) with some minor changes. A Fungus Genomic DNA Extraction Kit (Biomiga#GD2416, San Diego, California, USA) was used to extract fungal genome DNA. DNA amplification was performed in a 25 µl reaction mixture which contains 2.5 µl 10 × PCR buffer, 1 µl of each primer (10 µM), 1 µl template DNA and 0.25 µl Taq DNA polymerase (Promega, Madison, WI, USA). The ITS rDNA region was amplified using primer pairs ITS4 and ITS5 (White et al. 1990). The partial tub2 gene region was amplified with primer pairs T1 and Bt2b (Glass and Donaldson 1995, O'Donnell and Cigelnik 1997). The tef1 gene fragment was amplified using the primer pairs EF1-728F and EF-2 (O'Donnell et al. 1998, Carbone and Kohn 1999). PCR amplification conditions were performed according to the methods described by Norphanphoun et al. (2019). The PCR products were sent to SinoGenoMax company (Beijing, China) which used the fluorescently-labelled Sanger method for sequencing. The resulting DNA sequences were submitted to GenBank (https://www.ncbi.nlm.nih.gov/genbank/) and their accession numbers were provided in Table 1.

Table 1.

The reference sequences used for phylogenetic analyses in this study with their GenBank accession numbers. (T) = ex-type strain.

Species name Strain number GenBank Accession numbers Reference
ITS tub2 tef1
Neopestalotiopsis acrostichi MFLUCC 17-1754T MK764272 MK764338 MK764316 Norphanphoun et al. (2019)
MFLUCC 17-1755 MK764273 MK764339 MK764317 Norphanphoun et al. (2019)
N. alpapicalis MFLUCC 17-2544 MK357772 MK463545 MK463547 Kumar et al. (2019)
MFLUCC 17-2545 MK357773 MK463546 MK463548 Kumar et al. (2019)
N. aotearoa CBS 367.54T KM199369 KM199454 KM199526 Maharachchikumbura et al. (2014)
HNPeHNLD2001 MT764947 MT796262 MT800516 Direct submission
N. asiatica MFLUCC 12-0286T JX398983 JX399018 JX399049 Maharachchikumbura et al. (2012)
N. australis CBS 114159T KM199348 KM199432 KM199537 Maharachchikumbura et al. (2014)
N. brachiata MFLUCC 17-1555T MK764274 MK764340 MK764318 Norphanphoun et al. (2019)
N. brasiliensis COAD 2166T MG686469 MG692400 MG692402 Bezerra et al. (2018)
N. chiangmaiensis MFLUCC 18-0113T - MH412725 MH388404 Tibpromma et al. (2018)
N. chrysea MFLUCC 12-0261T JX398985 JX399020 JX399051 Maharachchikumbura et al. (2012)
N. clavispora MFLUCC 12-0281T JX398979 JX399014 JX399045 Maharachchikumbura et al. (2012)
CBS 447.73 KM199374 KM199443 KM199539 Maharachchikumbura et al. (2014)
N. cocoes MFLUCC 15-0152T KX789687 - KX789689 Hyde et al. (2016)
N. coffea-arabicae HGUP4015T KF412647 KF412641 KF412644 Song et al. (2013)
N. cubana CBS 600.96T KM199347 KM199438 KM199521 Maharachchikumbura et al. (2014)
N. dendrobii MFLUCC 14-0106T MK993571 MK975835 MK975829 Ma et al. (2019)
MFLUCC 14-0132 MK993572 - MK975830 Ma et al. (2019)
N. egyptiaca COAD 2167 MG686470 MG692401 MG692403 Silva et al. (2018)
N. ellipsospora MFLUCC 12-0284 JX398981 JX399015 JX399046 Maharachchikumbura et al. (2012)
MFLUCC 12-0283T JX398980 JX399016 JX399047 Maharachchikumbura et al. (2012)
N. eucalypticola CBS 264.37T KM199376 KM199431 KM199551 Maharachchikumbura et al. (2014)
N. foedans CGMCC3.9178 JX398989 JX399024 JX399055 Maharachchikumbura et al. (2014)
CGMCC3.9123T JX398987 JX399022 JX399053 Maharachchikumbura et al. (2014)
N. formicarum CBS 362.72T KM199358 KM199455 KM199517 Maharachchikumbura et al. (2014)
CBS 115.83 KM199344 KM199444 KM199519 Maharachchikumbura et al. (2014)
N. honoluluana CBS 111535 KM199363 KM199461 KM199546 Maharachchikumbura et al. (2014)
CBS 114495T KM199364 KM199457 KM199548 Maharachchikumbura et al. (2014)
N. iranensis CBS 137768T KM074048 KM074057 KM074051 Ayoubi and Soleimani (2016)
N. javaensis CBS 257.31T KM199357 KM199437 KM199543 Maharachchikumbura et al. (2014)
MFLUCC 12-0594 KX816905 KX816933 KX816874 Maharachchikumbura et al. (2014)
N. keteleeria MFLUCC 13-0915 KJ503820 KJ503821 KJ503822 Song et al. (2014)
N. macadamiae BRIP 63737cT KX186604 KX186654 KX186627 Akinsanmi et al. (2017)
BRIP 63757a KX186592 KX186674 KX186647 Akinsanmi et al. (2017)
N. magna MFLUCC 12-0652T KF582795 KF582793 KF582791 Maharachchikumbura et al. (2014)
N. mesopotamica CBS 336.86T KM199362 KM199441 KM199555 Maharachchikumbura et al. (2014)
CBS 299.74 KM199361 KM199435 KM199541 Maharachchikumbura et al. (2014)
N. musae MFLUCC 15-0776T KX789683 KX789686 KX789685 Hyde et al. (2016)
N. natalensis CBS 138.41T KM199377 KM199466 KM199552 Maharachchikumbura et al. (2014)
N. nebuloides BRIP 66617T MK966338 MK977632 MK977633 Crous et al. (2020)
N. pandanicola KUMCC 17-0175T - MH412720 MH388389 Tibpromma et al. (2018)
N. pernambucana URM7148 - - KU306739 Silvério et al. (2016)
N. petila MFLUCC 17-1737T MK764275 MK764341 MK764319 Norphanphoun et al. (2019)
MFLUCC 17-1738 MK764276 MK764342 MK764320 Norphanphoun et al. (2019)
N. phangngaensis MFLUCC 18-0119T MH388354 MH412721 MH388390 Tibpromma et al. (2018)
MFLUCC 19-2741 - MW148259 MW192200 Direct submission
N. piceana CBS 394.48T KM199368 KM199453 KM199527 Maharachchikumbura et al. (2014)
CBS 254.32 KM199372 KM199452 KM199529 Maharachchikumbura et al. (2014)
N. protearum CBS 114178T JN712498 KM199463 KM199542 Maharachchikumbura et al. (2014)
CBS 111506 MH553959 MH554618 MH554377 Liu et al. (2019)
N. rhapidis GUCC 21501 MW931620 MW980441 MW980442 This study
N. rhizophorae MFLUCC 17-1551T MK764277 MK764343 MK764321 Norphanphoun et al. (2019)
MFLUCC 17-1550 MK764278 MK764344 MK764322 Norphanphoun et al. (2019)
N. rhododendri GUCC 21504 MW979577 MW980443 MW980444 This study
GUCC 21505 MW979576 MW980445 MW980446 This study
N. rosae CBS 101057T KM199359 KM199429 KM199523 Maharachchikumbura et al. (2014)
CBS 124745 KM199360 KM199430 KM199524 Maharachchikumbura et al. (2014)
N. rosicola CFCC 51992 KY885239 KY885245 KY885243 Jiang et al. (2018)
CFCC 51993 KY885240 KY885246 KY885244 Jiang et al. (2018)
N. samarangensis CBS 115451 KM199365 KM199447 KM199556 Maharachchikumbura et al. (2014)
SS010 JQ968609 JQ968610 JQ968611 Direct Submission
N. saprophytica CBS 115452 KM199345 KM199433 KM199538 Maharachchikumbura et al. (2014)
GUCC 21506 MW979578 MW980447 MW980449 This study
GUCC 21507 MW979579 MW980448 MW980450 This study
N. sichuanensis CFCC 54338 MW166231 MW218524 MW199750 Jiang et al. (2021)
SM15-1C MW166232 MW218525 MW199751 Jiang et al. (2021)
N. sonneratae MFLUCC 17-1744T MK764279 MK764345 MK764323 Norphanphoun et al. (2019)
MFLUCC 17-1745 MK764280 MK764346 MK764324 Norphanphoun et al. (2019)
Neopestalotiopsis sp.1 CFCC 54337 MW166233 MW218526 MW199752 Jiang et al. (2021)
ZX12-1 MW166234 MW218527 MW199753 Jiang et al. (2021)
Neopestalotiopsis sp.2 CFCC 54340 MW166235 MW218528 MW199754 Jiang et al. (2021)
ZX22B MW166236 MW218529 MW199755 Jiang et al. (2021)
Neopestalotiopsis sp. nov. GUCC 210001 MW930715 MZ683390 MZ683389 Direct Submission
Neopestalotiopsis sp. nov. GUCC 210002 MW930716 MZ683391 MZ203452 Direct Submission
Neopestalotiopsis sp. nov. GUCC 210003 MW936717 MZ683392 MZ540914 Direct Submission
N. steyaertii IMI 192475T KF582796 KF582794 KF582792 Jiang et al. (2021)
N. surinamensis CBS 450.74T KM199351 KM199465 KM199518 Maharachchikumbura et al. (2014)
CBS 111494 - KM199462 KM199530 Maharachchikumbura et al. (2014)
N. thailandica MFLUCC 17-1730T MK764281 MK764347 MK764325 Norphanphoun et al. (2019)
MFLUCC 17-1731 MK764282 MK764348 MK764326 Norphanphoun et al. (2019)
N. umbrinospora MFLUCC 12-0285T JX398984 JX399019 JX399050 Maharachchikumbura et al. (2014)
N. vitis MFLUCC 17-1108 MG807045 MG859849 MG859769 Jayawardena et al. (2016)
N. zimbabwana CBS 111495T - KM199456 KM199545 Maharachchikumbura et al. (2014)
Pestalotiopsis diversiseta MFLUCC 12-0287T JX399009 JX399040 JX399073 Maharachchikumbura et al. (2012)
P. trachicarpicola OP068T JQ845947 JQ845945 JQ845946 Zhang et al. (2012)

Sequence alignment and phylogenetic analyses

The reference sequences were downloaded from GenBank for phylogenetic analyses (Table 1). Multiple sequence alignments were generated with MAFFT v. 7.307 online version (Katoh and Standley 2016) and manually improved in MEGA v. 6.06, where necessary (Tamura et al. 2013). Concatenated multi-locus datasets for the three gene regions were aligned using Mesquite v. 2.75 (Maddison 2008). Manual improvement, when necessary, was done using AliView (Larsson 2014). Terminal ends and ambiguous regions of the alignment were deleted manually. Phylogenetic analyses were performed using concatenated sequences of the three loci (ITS, tub2 and tef1) with Maximum Likelihood (ML), Maximum Parsimony (MP) and Bayesian Inference (BI).

Maximum Likelihood analysis was performed at the CIPRES Science Gateway web portal (Miller et al. 2010) using RAxML-HPC BlackBox v. 8.2.12 with the GTR+G+I model and 1,000 rapid bootstrap (BS) replicates (Stamatakis 2014).

Bayesian analysis was conducted with MrBayes v. 3.1.2 (Huelsenbeck and Ronqvist 2001). Parameters of Bayesian analysis in MrBayes v. 3.2; Markov chains were run for 1000000 generations and trees were sampled every 100th generation (printfreq = 100) and 10000 trees were obtained. The last standard deviation of split frequencies was below 0.01. Initial trees were discarded (25% burn-in value) and the remaining trees were used to evaluate posterior probabilities (PP) in the majority rule consensus tree.

PAUP v. 4.0b10 (Swofford 2002) was used to perform Maximum Parsimony (MP) analyses. Trees were inferred by using the heuristic search option with 1,000 random sequence additions and tree bisection and reconnection (TBR) as the branch-swapping algorithm. The maxtrees were set as 5000. Descriptive tree statistics for parsimony (tree length (TL), consistency index (CI), retention index (RI), related consistency index (RC) and homoplasy index (HI)) were calculated.

Taxon treatments

Neopestalotiopsis rhapidis Qi Yang & Yong Wang bis, sp. nov.

Material    Download as CSV 
Holotype:
  1. scientificName:
    Neopestalotiopsis rhapidis
    ; order:
    Amphisphaeriales
    ; family:
    Sporocadaceae
    ; genus:
    Neopestalotiopsis
    ; country:
    China
    ; stateProvince:
    Guangxi
    ; locality:
    Nanning City, Guangxi Medicinal Botanical Garden
    ; verbatimCoordinates:
    108°19’ E,22°51’ N
    ; recordedBy:
    Qi Yang
    ; identifiedBy:
    Qi Yang
    ; dateIdentified:
    2021
    ; collectionID:
    HGUP 332
    ; occurrenceID:
    GUCC 21501

Description

Disease symptom: Pathogenic causing spots on leaves tip of Rhapis excelsa. Leaf spots shape irregular, brown, slightly sunken on leaves tip. Small brown spots appeared initially and then gradually enlarged, changing to dark brown spots with a yellow border and jagged edge.

Colonies on PDA reach 7.5–8 cm in diam. after 7 d at room temperature (28°C), under light 12 hr/dark. Colonies filamentous to circular, whitish, with clustered black fruiting bodies and filiform and fluffy margin, white from above and light yellow from the reverse. Sexual morph: undetermined. Asexual morph(Fig. 1): Conidiomata 560–1405 µm in diam., pycnidial, globose, solitary, black, semi-immersed on PDA, exuding brown to dark brown conidia. Conidiophores branched or unbranched, hyaline, thin-walled. Conidiogenous cell discrete to lageniform, obclavate, hyaline or rarely light brown, smooth-walled. Conidia (22–)25.5 × 4(–6) µm (x̄ = 23 × 5.2 µm, n = 30), fusiform to clavate, straight to slightly curved, 4-septate; basal cell cylindrical to obconic, hyaline, thin-walled, smooth, 3–5 µm (x̄ = 3.7 µm, n = 30); the three median cells 11.5–15 µm (x̄ = 13.3 µm, n = 30), dark brown with septa darker than the rest of the cells, the second cell from base 3–5 µm (x̄ = 4 µm, n = 30); the third cell 2.5–6 µm (x̄ = 3.9 µm, n = 30); the fourth cell 3–4.5 µm (x̄ = 3.8 µm, n = 30); apical cell 2–4.5 µm (x̄ = 3.3 µm, n = 30), cylindrical, hyaline; 2–3 (mostly 3) tubular apical appendages, arising from the apex of the apical cell each at different points, flexuous, 11–16 µm (x̄ = 13.6 µm, n = 30); basal appendage present, single, tubular, unbranched, 2–5.5 µm (x̄ = 4 µm, n = 30).

Figure 1.  

Neopestalotiopsis rhapidis (GUCC 21501). a. Leaf spots of Neopestalotiopsis rhapidis; b, c. Culture on PDA (b-above, c-reverse); d. Colony sporulating on PDA; e–g. Conidiophores; h–k. Conidia. Scale bars: d = 1000 µm, e–k = 20 µm.

Etymology

Latin, rhapidis, refers to the host plant (Rhapis excelsa) from which the fungus was isolated.

Notes

Neopestalotiopsis rhapidis clustered with N. cocoes (MFLUCC 15-0152) with 85% ML support, although without enough MP and BI support. Within comparison of the three gene regions, there were only three character differences in the ITS region, but 27 in the tef1 region. Neopestalotiopsis rhapidis has longer conidia and shorter apical appendages than those of N. cocoes (19–22.5 ×7.5–9.5 µm; 14.9–21 µm) (Hyde et al. 2016). Thus, Neopestalotiopsis rhapidis (GUCC 21501) is introduced as a new species herein.

Neopestalotiopsis rhododendri Qi Yang & Yong Wang bis, sp. nov.

Materials    Download as CSV 
Holotype:
  1. scientificName:
    Neopestalotiopsis rhododendri
    ; order:
    Amphisphaeriales
    ; family:
    Sporocadaceae
    ; genus:
    Neopestalotiopsis
    ; country:
    China
    ; stateProvince:
    Yunnan
    ; locality:
    Kunming
    ; verbatimCoordinates:
    102°72’ E,25°05’ N
    ; recordedBy:
    Qi Yang
    ; identifiedBy:
    Qi Yang
    ; dateIdentified:
    2021
    ; collectionID:
    HGUP 134
    ; occurrenceID:
    GUCC 21504
Other material:
  1. scientificName:
    Neopestalotiopsis rhododendri
    ; order:
    Amphisphaeriales
    ; family:
    Sporocadaceae
    ; genus:
    Neopestalotiopsis
    ; country:
    China
    ; stateProvince:
    Guizhou
    ; locality:
    Kaili
    ; verbatimCoordinates:
    107°97’ E,26°58’ N
    ; recordedBy:
    Qi Yang
    ; identifiedBy:
    Qi Yang
    ; dateIdentified:
    2021
    ; collectionID:
    HGUP 997
    ; occurrenceID:
    GUCC 21505

Description

Disease symptom: Associated with leaf spots of Rhododendron simsii. The leaf spots are small irregular to subcircular shape, brown, slightly sunken spots appear on surface leaves of R. simsii, which scattered on the surface leaves tip and eventually develops into a large lesion. Small off-white spots appeared initially and then gradually enlarged, changing to light brown circular ring spots with a dark brown border.

Colonies on PDA reaching 6.5–7 cm in diam. after 7 d at room temperature (28°C), under light 12 hr/dark. Hyphae white, colonies filamentous to circular, slightly undulate at the edge, with black fruiting bodies clustered, has filiform and fluffy margin, white from above and light yellow from the reverse. Sexual morph: undetermined. Asexual morph(Fig. 2): Conidiomata 55–280 µm in diam., pycnidial, globose, solitary, black, semi-immersed on PDA, exuding brown to dark brown mass of conidia. Conidiophores often reduced to conidiogenous cell, regularly septate and branched at the base. Conidiogenous cells mostly integrated, ampulliform, cylindrical, hyaline to light brown, smooth-walled. Conidia (25.5–)30 × 5(–6) µm (x̄ = 27.6 × 5.5 µm, n = 30), fusiform to clavate, straight to slightly curved, 4-septate; basal cell obconic, hyaline, thin-walled, smooth, 3.5–6.5 µm (x̄ = 4.5 µm, n = 30); the three median cells 13.5–19.5 µm (x̄ = 16.3 µm, n = 30), light brown to dark brown, dark brown with septa darker than the rest of the cells, the second cell from base 4–6 µm (x̄ = 5 µm, n = 30); the third cell 3.5–5.5 µm (x̄ = 4.5 µm, n = 30); the fourth cell 4–6.5 µm (x̄ = 4.8 µm, n = 30); apical cell 3.5–6.3 µm (x̄ = 5 µm, n = 30), cylindrical to sub-cylindrical, hyaline, 1–3 (mostly 2) tubular apical appendages, arising from the apex of the apical cell each at different points, 21–38.5 µm (x̄ = 29.2 µm, n = 30); basal appendage present most of the time, single, tubular, unbranched, 6–11.5 µm (x̄ = 8.5 µm, n = 30).

Figure 2.  

Neopestalotiopsis rhododendri (GUCC 21504). a, b, c. Leaf spots of Neopestalotiopsis rhododendri; d, e. Culture on PDA (d-above, e-reverse); f. Colony sporulating on PDA; g–h. Conidia and conidiophores; i–m. Conidia. Scale bars: f = 1000 µm, g–m = 20 µm.

Etymology

China, Yunnan Province, Kunming City, from leaves of Rhododendron simsii, 12 February 2018, Q. Zhang, HGUP 134, holotype, ex-type living culture GUCC 21504.

Notes

In the multi-gene analysis, strain GUCC 21504 formed a distinct clade with a sister strain GUCC 21505, but the node support values were 68/90/- (MP/ML/BI) and these two strains were close to N. protearum (CBS 114178). When comparing the polymorphic nucleotide differences of our two strains, there are 18 base pair differences, seven in ITS, two in tub2 and nine in tef1, but without obvious distinction (higher than 98.5%). Compared with N. protearum and our ex-type strain (GUCC 21504), there were six character differences with N. protearum in the ITS region, three character differences with N. protearum in the tub2 region, but 12 character differences from N. protearum in the tef1 region; thus the DNA base pair differences were mainly in the tef1 gene regions. The morphological differences between our strains and N. protearum were wider conidia (N. protearum: 24.8 ± 1.5 × 8.5 ± 0.6 µm), more apical appendages (N. protearum: 3–5) and shorter basal appendages (N. protearum: 5–8 µm) (Maharachchikumbura et al. 2014). Thus, Neopestalotiopsis rhododendri is introduced as a novel taxon, based on morphology and phylogeny.

Neopestalotiopsis saprophytica (Maharachch. & K.D. Hyde) Maharachch., K.D. Hyde & Crous, 2014

Materials    Download as CSV 
  1. scientificName:
    Neopestalotiopsis saprophytica
    ; order:
    Amphisphaeriales
    ; family:
    Sporocadaceae
    ; genus:
    Neopestalotiopsis
    ; country:
    China
    ; stateProvince:
    Guangxi
    ; locality:
    Nanning City,Guangxi Medicinal Botanical Garden
    ; verbatimCoordinates:
    108°19’ E,22°51’ N
    ; recordedBy:
    Qi Yang
    ; identifiedBy:
    Qi Yang
    ; dateIdentified:
    2021
    ; collectionID:
    HGUP 423
    ; occurrenceID:
    GUCC 21506
  2. scientificName:
    Neopestalotiopsis saprophytica
    ; order:
    Amphisphaeriales
    ; family:
    Sporocadaceae
    ; genus:
    Neopestalotiopsis
    ; country:
    China
    ; stateProvince:
    Guangxi
    ; locality:
    Nanning City,Guangxi Medicinal Botanical Garden
    ; verbatimCoordinates:
    108°19’ E,22°51’ N
    ; recordedBy:
    Qi Yang
    ; identifiedBy:
    Qi Yang
    ; dateIdentified:
    2021
    ; collectionID:
    HGUP 133
    ; occurrenceID:
    GUCC 21507

Description

Disease symptom: Pathogenic causing spots on leaves of Erythropalum scandens. Leaf spots shape irregular, brown to reddish-brown, slightly sunken spots appear on surface leaves of E. scandens, which scattered on the leaves tip. Small brown spots appeared initially and then gradually enlarged, changing to reddish-brown spots with a yellow border.

Colonies on PDA reaching 7.5–8 cm in diam. after 7 d at room temperature (28℃), under light 12 hr/dark. Hyphae change from light pink to off-white. Colonies filamentous to circular, slightly undulate at the edge, with black fruiting bodies clustered, filiform margin, light pink from above and light yellow from the reverse. Sexual morph: undetermined. Asexual morph (Fig. 3): Conidiomata up to 280 μm in diam., pycnidial, globose, solitary, black, semi-immersed on PDA, exuding brown to dark brown mass of conidia. Conidiophores branched or unbranched, hyaline, thin-walled. Conidiogenous cells discrete, ampulliform to lageniform, hyaline, thin-walled, smooth. Conidia (21.5–)26.5 × 4.5(–6.5) µm (x̄ = 23.2 × 5.2 µm, n = 30), fusiform to clavate, straight to slightly curved, 4-septate; basal cell obconic, hyaline or sometimes pale brown, thin-walled, smooth, 3–5 µm (x̄ = 4 µm, n = 30); the three median cells 13–17 µm (x̄ = 14.9 µm, n = 30), pale brown to brown, dark brown with septa darker than the rest of the cells, the second cell from base 4–6.5 µm (x̄ = 4.9 µm, n = 30); the third cell 3–5 µm (x̄ = 4.1 µm, n = 30); the fourth cell 3.5–6 µm (x̄ = 4.8 µm, n = 30); apical cell 3–5 µm (x̄ = 3.9 µm, n = 30), cylindrical, hyaline; 1–4 (mostly 3) tubular apical appendages, arising from the apex of the apical cell each at different point, flexuous, 18–28.5 µm (x̄ = 22.4 µm, n = 30); basal appendage present most of the time, single, tubular, unbranched, 3.3–7 µm (x̄ = 4.3 µm, n = 30).

Figure 3.  

Neopestalotiopsis saprophytica (GUCC 21506). a, b, c. Leaf spots of Neopestalotiopsis saprophytica; d, e. Culture on PDA (d-above, e-reverse); f. Colony sporulating on PDA; g–h. Conidia and conidiophores; i–m. Conidia. Scale bars: f = 1000 µm, g–m = 20 µm.

Notes

GUCC 21506 and GUCC 21507 with the same nucleotides sequences were related to N. dendrobii (MFLUCC 14-0106) and N. saprophytica (CBS 115452). There were ten character differences with N. dendrobii and 11 character differences with N. saprophytica, but the most differences (nine character differences) between our strains and N. saprophytica were only in the tef1 region. Alternatively, collection differed to N. dendrobii in having more apical appendages (N. dendrobii: 2–3) and much longer apical appendages (N. dendrobii: 6 ± 0.9 µm) (Ma et al. 2019). Morphological characters of our collections and N. saprophytica overlapped (Maharachchikumbura et al. 2014). Thus, GUCC 21506 and GUCC 21507 are considered as N. saprophytica.

Analysis

Phylogenetic analyses

The final dataset consists of 57 taxa, including Pestalotiopsis diversiseta (MFLUCC 12-0287) and P. trachicarpicola (OP068) as the outgroup taxa. It comprised 2052 characters including gaps (tef1: 1−606, tub2: 607−1443 and ITS: 1444−2052). There were 1426 constant, 284 parsimony uninformative and 342 parsimony informative characters (TL = 1225 steps, CI = 0.66, RI = 0.70, RC= 0.46 and HI= 0.34). The most parsimonious tree generated from combined ITS, tub2 and tef1 sequence data of species of Neopestalotiopsis is shown in Fig. 4.

Figure 4.  

The phylogram generated from MP analysis, based on combined ITS, tub2 and tef1 sequence data of Neopestalotiopsis. The tree was rooted with Pestalotiopsis diversiseta (MFLUCC 12-0287) and P. trachicarpicola (OP068). Maximum Parsimony and Maximum Likelihood bootstrap values ≥ 50%, Bayesian posterior probabilities ≥ 0.90 (MPBS/MLBS/PPBY) were given at the nodes. Our strains in this study were in green. Ex-type strains were marked by T.

In the phylogenetic analyses, GUCC 21501 was sister to N. cocoes (MFLUCC 15-0152T), but only with a 85% ML bootstrap support. GUCC 21504 and GUCC 21505 formed an independent clade with MP and ML (68/90) supports and were close to N. protearum (CBS 111506T). GUCC 21506 and GUCC 21507 clustered with moderate and high supports (65/99/1: MP/ML/BI) and kept a very close relationship with N. saprophytica (CBS 115452) by credible statistic support (100/67/1: MP/ML/BI). DNA sequence differences between our strains and related species are listed in Table 2.

Table 2.

DNA sequence differences of the three gene regions between our strains and related species.

Species Strain number tef1 tub2 ITS
(characters: 1-606) (characters: 607-1443) (characters: 1444-2052)
N. rhapidis GUCC 21501 0 0 0
N. cocoes MFLUCC 15-0152T 27 (gaps: 2) - 3 (gaps: 3)
Species Strain number tef1 tub2 ITS
(characters: 1-606) (characters: 607-1443) (characters: 1444-2052)
N. saprophytica GUCC 21506 0 0 0
GUCC 21507 0 0 0
N. dendrobii MFLUCC 14-0106T 5 (gaps: 3) 4 (gap: 1) 1 (gap: 0)
N. saprophytica CBS 115452 9 (gaps: 3) 1 (gap: 0) 1 (gap: 1)
Species Strain number tef1 tub2 ITS
(characters: 1-606) (characters: 607-1443) (characters: 1444-2052)
N. rhododendri GUCC 21504 0 0 0
GUCC 21505 9 (gap: 0) 2 (gap: 0) 7 (gap: 1)
N. protearum CBS 114178T 12 (gaps: 6) 3 (gap: 0) 9 (gaps: 2)

Discussion

Hu et al. (2007) believed that pestalotiopsis-like fungi had different phenotypes in conidial morphology. Maharachchikumbura et al. (2014) summarised some stable characteristics for determining pestaloids, such as the length and width of conidia, length of the apical appendages, presence or absence of knobbed apices and the position of the apical appendage attached to the conidial body. However, as these characteristics were often similar or overlapped, sequence data are crucial for the identification of pestalotioid, and as well as for the introduction of new species (Norphanphoun et al. 2019).

In this study, we describe two new species as Neopestalotiopsis rhapidis and N. rhododendri. The species were distinct from extant Neopestalotiopsis species, based on morphological and phylogenetic analyses. However, the statistical support of main nodes for the genus were very low (Fig. 4). The reason might be that the reference sequences we used were short, including the short tef1 and tub2 sequences (Ran et al. 2017). Longer sequences with more informative data are needed to solve this problem. Furthermore, our study also found that the evolutionary relationships amongst species of Neopestalotiopsis are unstable (Maharachchikumbura et al. 2014, Jiang et al. 2018, Kumar et al. 2019, Tsai et al. 2020). Therefore, other genes are needed to distinguish the inter-species relationships in Neopestalotiopsis (Maharachchikumbura et al. 2014, Kumar et al. 2019, Norphanphoun et al. 2019).

Several indicators could be used in the classification of Neopestalotiopsis in this study, such as the size of conidia and the number and length of appendages (Maharachchikumbura et al. 2014, Freitas et al. 2019, Kumar et al. 2019). The differences in the colour of three median cells and the length of other cells, however, lacked significant variation to clearly distinguish the species of Neopestalotiopsis. Therefore, as the morphological identification alone cannot accurately identify the fungi of the genus Neopestalotiopsis, it must be combined with the phylogenetic tree (Liu et al. 2019, Norphanphoun et al. 2019, Tsai et al. 2020, Jiang et al. 2021).

Acknowledgements

The research was supported by National Natural Science Foundation of China (No. 31972222, 31560489), Program of Introducing Talents of Discipline to Universities of China (111 Program, D20023), Talent Project of Guizhou Science and Technology Cooperation Platform ([2017]5788-5, [2019]5641 and [2020]5001) and Guizhou Science, Technology Department International Cooperation Basic Project ([2018]5806). We also thank Profs. Kevin D. Hyde and Sajeewa Maharachchikumbura for their help to improve this paper.

References